Inter-network interworking method, apparatus, and system
An inter-network interworking method, an apparatus, and a system are provided to ensure that a service is not interrupted when a terminal moves from a second network to a third network. When the terminal supports a NAS capability of the third network and/or a network name corresponding to the terminal supports interworking between the second network and the third network, a second access management network element sends a session management request including a session identifier to a first session management network element that supports interworking of the terminal among a first network, the second network, and the third network. The second access management network element receives, from the first session management network element, a session management response including a session context of the terminal in the third network.
1 . An inter-network interworking method, comprising:
sending, by a second access management network element in a second network, a session management request to a first session management network element in accordance with a terminal supporting:
a non-access stratum (NAS) capability of a third network, and/or
a network name corresponding to the terminal supports interworking between the second network and the third network,
wherein the first session management network element supports interworking of the terminal among a first network, the second network, and the third network;
receiving, by the second access management network element from the first session management network element, a session management response to the session management request, wherein the session management response comprises a session context of a session of the terminal in the third network; and
preparing, by the second access management network element in accordance with the terminal moving to the second network, the session context of the terminal in the third network in advance of the terminal moving from the second network to the third network,
wherein the session management request comprises both:
a session identifier that is used to identify the session of the terminal in the third network, and the session context of the session of the terminal in the third network corresponds to the session identifier; and
a second indication information that is used to indicate to the terminal to move from the first network to the second network.
2 . The method according to claim 1 , wherein before the sending, by the second access management network element, the session management request to the first session management network element, the method further comprises:
receiving, by the second access management network element, address information of the first session management network element from a first access management network element in the first network.
3 . The method according to claim 1 , wherein before the sending, by the second access management network element, the session management request to the first session management network element, the method further comprises:
determining, by the second access management network element, that the terminal supports the NAS capability of the third network and/or the network name corresponding to the terminal supports the interworking between the second network and the third network, wherein a second session management network element selected, in the first network, by a first access management network element in the first network for the terminal does not support the interworking between the second network and the third network; and
selecting, by the second access management network element, the first session management network element.
4 . The method according to claim 1 , wherein the method further comprises:
receiving, by the second access management network element, a first request message from the terminal, wherein the first request message comprises a session identifier and/or first capability information, the first capability information indicates that the terminal supports the NAS capability of the third network, the session identifier is used to identify a session of the terminal in the third network, the session context is a context of the session corresponding to the session identifier, and the first request message is used to enable the terminal to move from the first network to the second network.
5 . The method according to claim 1 , wherein after the receiving, by the second access management network element, the session management response from the first session management network element, the method further comprises:
sending, by the second access management network element, the session context to the terminal.
6 . The method according to claim 1 , wherein the first network is a 2G network or a 3G network, the second network is a 4G network, and the third network is a 5G network.
7 . A communication apparatus, used in a second access management network element of a second network, wherein the apparatus comprises:
a processor; and
a non-transitory computer readable medium comprising computer-executable instructions that, when executed by the processor, facilitate the communication apparatus carrying out inter-network interworking operations comprising:
sending, by the second access management network element in a second network, a session management request to a first session management network element in accordance with a terminal supporting:
a non-access stratum (NAS) capability of a third network, and/or
a network name corresponding to the terminal supports interworking between the second network and the third network,
wherein the first session management network element supports interworking of the terminal among a first network, the second network, and the third network;
receiving, by the second access management network element from the first session management network element, a session management response to the session management request, wherein the session management response comprises a session context of a session of the terminal in the third network; and
preparing, by the second access management network element in accordance with the terminal moving to the second network, the session context of the terminal in the third network in advance of the terminal moving from the second network to the third network,
wherein the session management request comprises both:
a session identifier that is used to identify the session of the terminal in the third network, and the session context of the session of the terminal in the third network corresponds to the session identifier; and
a second indication information that is used to indicate to the terminal to move from the first network to the second network.
8 . The communication apparatus according to claim 7 , wherein before the sending, by the second access management network element, the session management request to the first session management network element, the operations further comprise:
receiving, by the second access management network element, address information of the first session management network element from a first access management network element in the first network.
9 . The communication apparatus according to claim 7 , wherein before the sending, by the second access management network element, the session management request to the first session management network element, the operations further comprise:
determining, by the second access management network element, that the terminal supports the NAS capability of the third network and/or the network name corresponding to the terminal supports the interworking between the second network and the third network, wherein a second session management network element selected, in the first network, by a first access management network element in the first network for the terminal does not support the interworking between the second network and the third network; and
selecting, by the second access management network element, the first session management network element.
10 . The communication apparatus according to claim 7 , wherein the operations further comprise:
receiving, by the second access management network element, a first request message from the terminal, wherein the first request message comprises a session identifier and/or first capability information, the first capability information indicates that the terminal supports the NAS capability of the third network, the session identifier is used to identify a session of the terminal in the third network, the session context is a context of the session corresponding to the session identifier, and the first request message is used to enable the terminal to move from the first network to the second network.
11 . The communication apparatus according to claim 7 , wherein after the receiving, by the second access management network element, the session management response from the first session management network element, the operations further comprise:
sending, by the second access management network element, the session context to the terminal.
12 . The communication apparatus according to claim 7 , wherein the first network is a 2G network or a 3G network, the second network is a 4G network, and the third network is a 5G network.