Handover method, apparatus, and system
Embodiments of this application provide a handover method. The method is performed by an access network device, and includes: determining that at least one terminal device is handed over from a first access network device to a second access network device, where the at least one terminal device accesses a network by using an IAB node; and sending first request information, where the first request information notifies a first access and mobility management function AMF network element to perform path handover on the at least one terminal device, and the first AMF network element serves the at least one terminal device. The first request information includes at least one first request message, and the at least one first request message is in one-to-one correspondence with the at least one terminal device.
1 . A method, applied to an access network device, the method comprising:
determining that at least one terminal device is handed over from a first access network device to a second access network device, wherein the at least one terminal device accesses a network through a first device;
sending first request information, wherein the first request information notifies a first mobility management network element to perform path handover on the at least one terminal device, and the first mobility management network element serves the at least one terminal device, wherein the first request information comprises at least one first request message, and the at least one first request message is in one-to-one correspondence with the at least one terminal device;
obtaining first device identification information, wherein the first device identification information identifies the first device;
determining a same first mobility management network element for each of the at least one terminal device based on the first device identification information; and
storing a correspondence between the first device identification information, identification information of the at least one terminal device, and identification information of the first mobility management network element, wherein sending the first request information comprises sending the first request information to the first mobility management network element based on the correspondence.
2 . The method according to claim 1 , wherein the method further comprises:
sending the correspondence between the identification information of the at least one terminal device and the identification information of the first mobility management network element to a second mobility management network element, wherein the second mobility management network element serves the first device.
3 . The method according to claim 1 , wherein the method further comprises:
sending second request information to the first mobility management network element, wherein the second request information comprises the first device identification information, and the first device identification information identifies the first device.
4 . The method according to claim 1 , wherein the first device is an integrated access and backhaul (IAB) node.
5 . A method, performed by a first mobility management network element, the method comprising:
receiving first request information, wherein the first request information notifies the first mobility management network element to perform path handover on at least one terminal device, the first mobility management network element serves the at least one terminal device, and the at least one terminal device accesses a network through a first device;
performing path handover on the at least one terminal device based on the first request information, wherein the first request information comprises at least one first request message, and the at least one first request message is in one-to-one correspondence with the at least one terminal device;
obtaining first device identification information, wherein the first device identification information identifies the first device;
storing a correspondence between the first device identification information, identification information of the at least one terminal device, identification information of a session management network element of the at least one terminal device, and identification information of a packet data unit (PDU) session; and
sending first session information to the session management network element based on the correspondence, wherein a context of a PDU session of the at least one terminal device is created based on the first session information, wherein the first session information comprises at least one first session message, and the first session message is in one-to-one correspondence with the PDU session of the at least one terminal device.
6 . The method according to claim 5 , wherein the method further comprises:
determining a same session management network element for each of the at least one terminal device based on the first device identification information.
7 . The method according to claim 5 , wherein the obtaining first device identification information further comprises:
receiving second request information, wherein the second request information comprises the first device identification information.
8 . The method according to claim 5 , wherein the first session information comprises the first device identification information.
9 . The method according to claim 5 , wherein the first device is an integrated access and backhaul (IAB) node.
10 . An apparatus, comprising:
at least one processor; and
at least one memory coupled to the at least one processor and configured to store programming instructions that, when executed by the at least one processor, cause the apparatus to:
determine that at least one terminal device is handed over from a first access network device to a second access network device, wherein the at least one terminal device accesses a network through a first device;
send first request information, wherein the first request information notifies a first mobility management network element to perform path handover on the at least one terminal device, and the first mobility management network element serves the at least one terminal device, wherein the first request information comprises at least one first request message, and the at least one first request message is in one-to-one correspondence with the at least one terminal device;
obtain first device identification information, wherein the first device identification information identifies the first device;
determine a same first mobility management network element for each of the at least one terminal device based on the first device identification information; and
store a correspondence between the first device identification information, identification information of the at least one terminal device, and identification information of the first mobility management network element, wherein sending the first request information comprises sending the first request information to the first mobility management network element based on the correspondence.
11 . The apparatus according to claim 10 , wherein the programming instructions that, when executed by the at least one processor, further cause the apparatus to:
send the correspondence between the identification information of the at least one terminal device and the identification information of the first mobility management network element to a second mobility management network element, wherein the second mobility management network element serves the first device.
12 . The apparatus according to claim 10 , wherein the programming instructions that, when executed by the at least one processor, further cause the apparatus to:
send second request information to the first mobility management network element, wherein the second request information comprises the first device identification information, and the first device identification information identifies the first device.
13 . The apparatus according to claim 10 , wherein the first device is an integrated access and backhaul (IAB) node.
14 . The apparatus according to claim 10 , wherein the apparatus is an access network device.