The first node: this node may be a relay node, or a function part of a distributed unit of a relay node, or a mobile terminal functional part of a relay node, or a distributed unit of a donor node (which may be the donor node connected before the configuration update or before the migration of the migrated node, or may be the donor node connected after the configuration update or after the migration of the migrated node). In an embodiment, the node may be a migrated node, that is, the parent node to which the node is connected has changed, for example, the relay node a in FIGS. 4A, 4B, and 4C. In another embodiment, the node may be a child node of the migrated relay node, the node is connected to the network through the migrated relay node, and the node is directly or indirectly connected to the migrated relay node (indirect connection refers to the connection of one or more nodes to the migrated relay node), for example, the relay nodes b and c referring to FIGS. 4A, 4B and 4C, the relay node b is directly connected to the relay node a, and the relay node c is indirectly connected to relay node a; in another embodiment, the node may be the parent node directly connected or indirectly connected to the migrated relay node (indirect connection refers to connection via the parent node connected by one or more nodes), such as the relay nodes 1 and 2 in FIGS. 4A, 4B, and 4Cc.
