Simultaneous registration to multiple networks
Systems, methods, apparatuses, and computer program products for simultaneous registration to multiple networks are provided. A user equipment (UE) may perform dual registration to multiple networks, e.g., a 5G system (5GS) of equivalent public land mobile networks (PLMNs), equivalent stand-alone non-public networks (SNPNs), or a combination of PLMNs and SNPNs. When a UE is registered to the first network, the UE may select the second network for a second registration based on one or more criteria.
1 . A user equipment, comprising:
at least one processor; and
at least one memory including computer program code which,
when executed by the at least one processor, causes the user equipment to perform operations, the operations comprising:
transmitting, to a first network node associated with a first network, a registration request message to register the user equipment with the first network, wherein the registration request message comprises at least:
an indication that the user equipment supports dual registration with two different networks; and
an identifier associated with the user equipment;
receiving, from the first network node, a registration accept message indicating the user equipment is registered with the first network, the registration accept message comprising at least:
one or more single network slice selection assistance information (S-NSSAI), wherein each respective S-NSSAI of the one or more S-NSSAIs is not supported by the first network; and
lists of identifiers of networks that support the one or more network slices that are not supported by the first network, wherein a respective list of the lists of identifiers of networks is associated with a respective S-NSSAI of the one or more S-NSSAIs that are not supported by the first network;
determining, based on configured network slice selection information in the user equipment, to use a S-NSSAI of the one or more S-NSSAIs that are not supported in the first network;
selecting a second network to register with, wherein the second network that is selected is identified by an identifier from among the list of identifiers of networks that is associated with the S-NSSAI that is selected;
transmitting, to a second network node associated with the second network that is selected, a second registration request message to register the user equipment with the second network, the second registration request message comprising the indication that the user equipment supports dual registration with two different networks; and
receiving, from the second network node, a second registration accept message indicating the user equipment is registered with the second network.
2 . The user equipment according to claim 1 , wherein the registration request message further comprises one or more cause values associated with the one or more S-NSSAI, wherein a respective cause value of the one or more cause values is associated with a respective S-NSSAI indicates the respective S-NSSAI is not available in the first network or is not available in a current registration area of the first network.
3 . The user equipment according to claim 1 , wherein the registration request message further comprises an identifier for the user equipment associated with the first network.
4 . The user equipment according to claim 1 , wherein the operations comprise, prior to the selecting:
determining to perform dual registration to the second network.
5 . The user equipment according to claim 4 , wherein the
second registration request message further comprises an identifier of the user equipment for the first network.
6 . The user equipment according to claim 1 , wherein the first network node comprises an access and mobility management function.
7 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code of a first network node associated with a first network,
wherein the computer program code when executed by the at least one processor, causes the apparatus to perform operations, the operations comprising:
receiving, from a user equipment, a registration request message,
wherein the registration request message comprises at least:
an indication that a user equipment supports dual registration with two different networks; and
an identifier associated with the user equipment; and
transmitting a registration accept message, the registration accept message indicating the user equipment is registered with the first network, the registration accept message comprising:
one or more single network slice selection assistance information (S-NSSAI), wherein each respective S-NSSAI of the one or more S-NSSAIs is not supported by the first network; and
lists of identifiers of networks that support the one or more network slices that are not supported by the first network, wherein a respective list of the lists of identifiers of networks is associated with a respective S-NSSAI of the one or more S-NSSAIs that are not supported by the first network.
8 . The apparatus according to claim 7 , wherein the registration request message further comprises one or more cause values associated with the one or more S-NSSAIs, wherein a respective cause value of the one or more cause values is associated with a respective S-NSSAI indicates the respective S-NSSAI is not available in the first network or is not available in a current registration area of the first network.
9 . The apparatus according to claim 7 , wherein the registration request message further comprises an identifier for the user equipment associated with the first network.
10 . The apparatus according to claim 7 , wherein the operations further comprise:
transmitting, to a unified data management function, a registration-related message to register a registration of the user equipment with the first network.
11 . A method, comprising:
transmitting, by a user equipment to a first network node associated with a first network, a registration request message to register the user equipment with the first network, wherein the registration request message comprises at least:
an indication that the user equipment supports dual registration with two different networks; and
an identifier for the user equipment associated with the user equipment;
receiving, by the user equipment from the first network node, a registration accept message indicating the user equipment is registered with the first network, the registration accept message comprising at least:
one or more single network slice selection assistance information (S-NSSAI), wherein each respective S-NSSAI of the one or more S-NSSAIs is not supported by the first network; and
lists of identifiers of networks that support the one or more network slices that are not supported by the first network, wherein a respective list of the lists of identifiers of networks is associated with a respective S-NSSAI of the one or more S-NSSAIs that are not supported by the first network;
determining, based on configured network slice selection information in the user equipment, to use a S-NSSAI of the one or more S-NSSAIs that are not supported in the first network;
selecting a second network to register with, wherein the second network that is selected is identified by an identifier from among the list of identifiers of networks that is associated with the S-NSSAI that is selected;
transmitting, to a second network node associated with the second network that is selected, a second registration request message to register the user equipment with the second network, the second registration request message comprising the indication that the user equipment supports dual registration with two different networks; and
receiving, from the second network node, a second registration accept message indicating the user equipment is registered with the second network.
12 . The method according to claim 11 , wherein the registration request message further comprises a cause value associated with each respective S-NSSAI of the one or more S-NSSAIs, wherein the cause value associated with a respective S-NSSAI indicates the respective S-NSSAI is not available in the first network or is not available in a current registration area of the first network.
13 . The method according to claim 11 , wherein each respective S-NSSAI is further associated with a cause value, and wherein the cause value associated with a respective S-NSSAI indicates the respective S-NSSAI is not available in the first network or is not available in a current registration area of the first netwo.
14 . The method according to claim 11 , further comprising:
prior to the selecting, determining to perform dual registration to the second network.
15 . The method according to claim 14 , wherein
the second registration request comprises an identifier of the user equipment for the first network.