US-12628058-B2 - Group migrating method and apparatus and system

US12628058B2US 12628058 B2US12628058 B2US 12628058B2US-12628058-B2

Abstract

A group migrating apparatus, configured in a second donor device, wherein the apparatus includes processor circuitry configured to, when a migrating IAB-node moves from a first donor device to the second donor device, perform at least one of the following processing enabling the migrating IAB-node to update a first TNL address used for a first F1-C connection to a second TNL address, enabling the migrating IAB-node to update a third TNL address used for a second F1-C connection to a fourth TNL address, configuring the migrating IAB-node with a fourth TNL address used for setting up a second F1-C connection, adding for the migrating IAB-node a second TNL address used for a first F1-C connection, configuring the migrating IAB-node with a third TNL address used for setting up a second F1-C connection, and adding for the migrating IAB-node a fourth TNL address used for a second F1-C connection.

Inventors

Yang Lu

Assignees

1FINITY INC.

Dates

Publication Date: 20260512
Application Date: 20230628

Claims (16)

1 . A group migrating apparatus, configured in a second donor device, wherein the apparatus comprises: processor circuitry configured to, when an IAB-node moves from a first donor device to the second donor device, perform at least one of the following processing: enabling the IAB-node to update a first TNL address used for a first F1-C connection to a second TNL address; enabling the IAB-node to update a third TNL address used for a second F1-C connection to a fourth TNL address; configuring the IAB-node with a fourth TNL address used for setting up a second F1-C connection; adding for the IAB-node a second TNL address used for a first F1-C connection; configuring the IAB-node with a third TNL address used for setting up a second F1-C connection; and adding for the IAB-node a fourth TNL address used for a second F1-C connection; wherein the first F1-C connection is F1 connection between a DU of the IAB-node and a CU of the first donor device, the second F1-C connection is F1 connection between the DU of the IAB-node and a CU of the second donor device, the first TNL address and the third TNL address are TNL addresses routable to the DU of the first donor device, and the second TNL address and the fourth TNL address are TNL addresses routable to the DU of the second donor device; wherein that the IAB-node moves from the first donor device to the second donor device refers to one of the following: that the IAB-node is connection reestablished to the second donor device when a radio link failure occurs in a backhaul link of the IAB-node under the first donor device; that the IAB-node is handed over from the first donor device to the second donor device; and that the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device; wherein in a case where the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device, the receiver receives a first RRC reconfiguration message; and wherein the first RRC reconfiguration message includes secondary cell group (SCG) configuration information and the second TNL address used for the first F1-C connection, and the IAB-node adds the second TNL address for the first F1-C connection.
2 . The apparatus according to claim 1 , wherein when the radio link failure occurs in the backhaul link of the IAB-node under the first donor device, the processor circuitry performs the following processing: enabling the IAB-node to update the first TNL address used for the first F1-C connection to the second TNL address; and configuring the IAB-node with the fourth TNL address used for setting up the second F1-C connection.
3 . The apparatus according to claim 1 , wherein, after the IAB-node is connection reestablished to the second donor device, the processor circuitry transmits a first RRC reconfiguration message to the IAB-node, the first RRC reconfiguration message containing the second TNL address used for the first F1-C connection, or the first RRC reconfiguration message containing the second TNL address used for the first F1-C connection and the fourth TNL address used for the second F1-C connection.
4 . The apparatus according to claim 3 , wherein after the second F1-C connection is setup between the second donor device and the IAB-node, the processor circuitry transmits a first message to the DU of the IAB-node at the CU of the second donor device via the second F1-C connection by using the fourth TNL address, so that the IAB-node sets up a second context for its served UE; wherein the first message includes a first context identifier of the UE, so that the IAB-node obtains a first context of the UE according to the first context identifier and sets up the second context by reusing the first context.
5 . A group migrating apparatus, configured in a IAB-node, the IAB-node moving from a first donor device to a second donor device, wherein the apparatus comprises: a receiver configured to receive, from the first donor device, a first message, the first message including at least one of the following: a second TNL address used for a first F1-C connection, so as to update a first TNL address used for the first F1-C connection to the second TNL address, or to add the second TNL address for the first F1-C connection; a fourth TNL address used for the second F1-C connection, so as to update a third TNL address used for the second F1-C connection to the fourth TNL address, or to set up the second F1-C connection with a CU of the second donor device by using the fourth TNL address, or to add the fourth TNL address for the second F1-C connection; and a third TNL address used for the second F1-C connection, so as to add the third TNL address for the second F1-C connection, or to set up the second F1-C connection with the CU of the second donor device by using the third TNL address; wherein the first F1-C connection is F1 connection between a DU of the IAB-node and a CU of the first donor device, the second F1-C connection is F1 connection between the DU of the IAB-node and the CU of the second donor device, the first TNL address and the third TNL address are TNL addresses routable to the first donor device, and the second TNL address and the fourth TNL address are TNL addresses routable to the second donor device; wherein the apparatus further comprises: first setting processor circuitry and second setting processor circuitry, the first setting processor circuitry setting up the second F1-C connection with the second donor device, the receiver receiving a second message transmitted by the CU of the second donor device via the second F1-C connection by using the fourth TNL address, and the second setting processor circuitry setting up a second context for a UE served by the IAB-node according to the second message; and wherein the second message includes a first context identifier of the UE, and the IAB-node obtains a first context of the UE according to the first context identifier and sets up the second context by reusing the first context.
6 . The apparatus according to claim 5 , wherein that the IAB-node moves from the first donor device to the second donor device refers to one of the following: that the IAB-node is connection reestablished to the second donor device when a radio link failure occurs in a backhaul link of the IAB-node under the first donor device; that the IAB-node is handed over from the first donor device to the second donor device; and that the IAB-node maintains connection with the first donor device and adds an interface connection with the second donor device.
7 . The apparatus according to claim 6 , wherein the apparatus further comprises processor circuitry, after the IAB-node is connection reestablished to the second donor device, the receiver receives the first message; and the first message includes the second TNL address used for the first F1-C connection, and the processor circuitry updates the first TNL address used for the first F1-C connection to the second TNL address; or, the first message includes the second TNL address used for the first F1-C connection and a fourth TNL address used for the second F1-C connection, and the processor circuitry updates the first TNL address used for the F1-C connection to the second TNL address and sets up the second F1-C connection with the CU of the second donor device by using the fourth TNL address.
8 . The apparatus according to claim 6 , wherein the apparatus further comprises: first setting processor circuitry and processor circuitry, and in a case where the IAB-node is handed over from the first donor device to the second donor device, the receiver receives the first message; the first message includes a handover command and the fourth TNL address used for the second F1-C connection, and the first setting processor circuitry sets up the second F1-C connection with the CU of the second donor device by using the fourth TNL address; or, the first message includes a handover command and the second TNL address used for the first F1-C connection, and the processor circuitry updates the first TNL address used for the first F1-C connection to the second TNL address.
9 . The apparatus according to claim 7 , wherein the first message further includes at least one of the following: a BAP address allocated to the IAB-node; backhaul RLC channel configuration of the IAB-node, and a default BAP routing identifier and default backhaul RLC channel identifier used for F1-C traffic and non-F1 traffic; a sixth TNL address used by the IAB-node to update a fifth TNL address used for its F1-U connection to the sixth TNL address; and a BAP routing identifier and a backhaul RLC channel identifier used for F1-U connection; wherein the fifth TNL address is a TNL address routable to a DU of the first donor device, and the sixth TNL address is a TNL address routable to a DU of the second donor device.
10 . The apparatus according to claim 7 , wherein the apparatus further comprises processor circuitry, and in a case where the IAB-node is handed over from the first donor device to the second donor device, the receiver receives the first message, the first message including a handover command and the fourth TNL address used for the second F1-C connection, and the processor circuitry updates the third TNL address used for the second F1-C connection to the fourth TNL address.
11 . The apparatus according to claim 7 , wherein in a case where the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device, the receiver receives the first message; wherein the first message includes secondary cell group (SCG) configuration information and a fourth TNL address or a third TNL address used for the second F1-C connection, and the apparatus further comprises first setting processor circuitry, the first setting processor circuitry setting up the second F1-C connection with the CU of the second donor device by using the fourth TNL address or the third TNL address; or, the first message includes secondary cell group (SCG) configuration information and the second TNL address used for the first F1-C connection, and the apparatus further comprises processor circuitry, the processor circuitry adding the second TNL address for the first F1-C connection.
12 . The apparatus according to claim 11 , wherein if the first message does not include the fourth TNL address used for the second F1-C connection, after the processor circuitry adds the air interface connection with the second donor device, the receiver receives a third message transmitted by the second donor device, wherein the third message includes the fourth TNL address used for the second F1-C connection; and the first setting processor circuitry sets up the second F1-C connection with the CU of the second donor device by using the fourth TNL address.
13 . The apparatus according to claim 7 , wherein in a case where the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device, the receiver receives the first message; wherein the first message includes secondary cell group (SCG) configuration information and a fourth TNL address used for the second F1-C connection, and the apparatus further comprises processor circuitry, the processor circuitry adding the fourth TNL address for the second F1-C connection; or, the first message includes secondary cell group (SCG) configuration information, the fourth TNL address used for the second F1-C connection and the second TNL address used for the first F1-C connection, and the apparatus further comprises processor circuitry, the processor circuitry adding the fourth TNL address for the second F1-C connection and adding the second TNL address for the first F1-C connection.
14 . The apparatus according to claim 5 , wherein the apparatus further comprises a transmitter, the receiver receives a RRC reconfiguration message for a UE served by the IAB-node forwarded by the first donor device via the first F1-C connection by using the second TNL address or by using the first TNL address, and the transmitter transmits the RRC reconfiguration message to the UE served by the IAB-node; and the receiver receives a RRC reconfiguration complete message transmitted by the UE served by the IAB-node, and the transmitter transmits the RRC reconfiguration complete message to the second donor device via the second F1-C connection by using the fourth TNL address.
15 . The apparatus according to claim 5 , wherein the apparatus further comprises a transmitter, the receiver receives a RRC reconfiguration message for the UE served by the IAB-node forwarded by the first donor device via the first F1-C connection by using the first TNL address, and the transmitter transmits the RRC reconfiguration message to the UE served by the IAB-node; and the receiver receives a RRC reconfiguration complete message transmitted by the UE served by the IAB-node, and the transmitter transmits the RRC reconfiguration complete message to the second donor device via the second F1-C connection by using the third TNL address or the fourth TNL address.
16 . A group migrating apparatus, configured in a first donor device, an IAB-node moving from the first donor device to a second donor device, wherein the apparatus comprises: a receiver configured to receive a second TNL address used for a first F1-C connection of the IAB-node transmitted by the second donor device; and processor circuitry configured to update a first TNL address used for the first F1-C connection of the IAB-node to the second TNL address, or add the second TNL address for the first F1-C connection of the IAB-node; wherein the first F1-C connection is F1 connection between a DU of the IAB-node and a CU of the first donor device, the first TNL address is a TNL address routable to the DU of the first donor device, and the second TNL address is a TNL address routable to the DU of the second donor device; wherein that the IAB-node moves from the first donor device to the second donor device refers to one of the following: that the IAB-node is connection reestablished to the second donor device when a radio link failure occurs in a backhaul link of the IAB-node under the first donor device; that the IAB-node is handed over from the first donor device to the second donor device; and that the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device; wherein in a case where the IAB-node maintains connection with the first donor device and adds an air interface connection with the second donor device, the receiver receives a first RRC reconfiguration message; and wherein the first RRC reconfiguration message includes secondary cell group (SCG) configuration information and the second TNL address used for the first F1-C connection, and the IAB-node adds the second TNL address for the first F1-C connection.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation application of International Application PCT/CN2021/071957 filed on Jan. 14, 2021, and designated the U.S., the entire contents of which are incorporated herein by reference. FIELD This disclosure relates to the field of communications. BACKGROUND Seamless cellular network deployment in the future needs very flexible and ultra-dense NR cell deployment. An ultra-dense network is one of goals of 5G, and deployment of an NR network with no wired backhaul is very important for the realization of 5G ultra-dense network. As coverage of a cell is reduced by a 5G millimeter wave, it is further needed that a wireless self-backhauling system is of multi-hop to meet deployment requirements. High bandwidth, large-scale MIMO and beam system of 5G make it easier for 5G to develop the wireless self-backhauling system of ultra-dense NR cells than LTE. In order to develop such multi-hop system with wireless self-backhauling, 3GPP began research and standardization of an IAB (integrated access and backhaul) project in R16. FIG. 1 is a schematic diagram of an IAB system. As shown in FIG. 1, in the IAB system, a relay node supports both access and backhaul functions. A wireless transmission link of the relay node multiplexes an access link and backhaul link in the time domain, frequency domain or spatial domain. The access link and backhaul link may use identical or different frequency bands. In an IAB network architecture, the relay node refers to an IAB-node, which supports both access and backhaul functions. A last hop of access node at the network side is referred to as an IAB-donor, which supports function of a gNB and supports IAB-node access. All UE data may be backhauled to the IAB-node in one or more hops via the IAB-node. Functions of the IAB-node are divided into two parts, one is a gNB-DU function, referred to as an IAB-DU, and the other is a UE function, referred to as an IAB-MT. The IAB-DU realizes function of a network side device, is connected to a downstream child IAB-node, provides NR air access to the UE and the downstream child IAB-node, and sets up F1 connection with the IAB donor-CU. The IAB-MT realizes some functions of a terminal equipment and is connected to an uplink parent IAB-node or IAB-donor DU. The IAB-MT includes physical layer, layer 2, RRC (Radio Resource Control) and NAS (Non-Access Stratum) layer functions, and is further indirectly connected to the IAB donor-CU and a core network. In IAB system, the IAB-node may access to the network in a standalone (SA) mode or a non-standalone (E-UTRA-NRDualConnectivity, EN-DC) mode. FIG. 2 is a schematic diagram of an IAB architecture of the SA mode. FIG. 3 is a schematic diagram of an IAB architecture of the EN-DC mode. FIG. 4 is a schematic diagram of an IAB-node, a parent IAB-node and a child IAB-node. As shown in FIG. 4, as a network side, an IAB-DU of the IAB-node is connected to IAB-MT to the child IAB-node, and as a terminal side, an IAB-MT of the IAB-node is connected to the IAB-DU of the parent IAB-node. FIG. 5 is a schematic diagram of an F1 user plane (F1-U) protocol stack between the IAB-DU and IAB-donor CU. FIG. 6 is a schematic diagram of an F1 control plane (F1-C) protocol stack between the IAB-DU and IAB-donor CU. As shown in FIG. 5 and FIG. 6, the F1-U and F1-C are built above a transmission (IP) layer between the IAB-DU and IAB-donor-CU. Two hops of wireless backhaul and one hop of wired backhaul are performed in FIG. 5 and FIG. 6. On the backhaul link, the transmission (IP) layer is carried on a backhaul adaptive protocol (BAP) sublayer. A BAP entity in the IAB-node realizes a routing function of the IAB system, and the IAB-donor CU provides a routing table. BAP PDUs (protocol data units) are transmitted in an RLC (radio link control) channel of the backhaul link, multiple RLC channels of the backhaul link may be configured by the IAB-donor to carry services of different priorities and QoS (Quality of Service), and the BAP entity maps the BAP PDUs to different backhaul RLC channels. It should be noted that the above description of the background is merely provided for clear and complete explanation of this disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of this disclosure. SUMMARY It was found by the inventors that an R16 IAB system has supported adaptive changes in topology and routing caused by movement of the IAB-node between different DUs under the same donor. When the IAB-node moves under the same donor (in such a case, the IAB-node is referred to as a migrating IAB-node), a topology relation with a downstream child IAB-node and UE is still maintained. Although the IAB-node may possibly be allocated a TNL (transmission network layer) address that can lead to a DU of a new donor, i.e. an IP address, for