Managing user equipment capabilities in single and multiple registration scenarios
A user equipment (UE) can implement a method for managing UE capability information. The method includes: registering ( 1702 ) with a first cellular network via a first RAN using a first universal subscriber identity module (USIM); registering ( 1704 ) with a second cellular network via a second RAN using a second USIM; transmitting ( 1706 ), to the first RAN, a first indication of a UE capability for communicating with the first RAN over a first RAT; and based on whether the UE supports communicating over a second RAT, which is different from the first RAT, while registered to both the first cellular network and the second cellular network, either: (i) transmitting ( 1710 ), to the first RAN, a second indication of a UE capability for communicating with the first RAN over the second RAT; or (ii) disabling ( 1712 ) UE capabilities dedicated to communicating over the second RAT.
1 . A method in a user equipment (UE) for managing UE capability information, the UE equipped with a first universal subscriber identity module (USIM) for communicating with a first cellular network and a second USIM for communicating with a second cellular network, the first cellular network including a first radio access network (RAN) and a first core network (CN), and the second cellular network including a second RAN and a second CN different from the first CN, the method comprising:
registering, by the UE, with the first cellular network via the first RAN using the first USIM;
registering with the second cellular network via the second RAN using the second USIM, so that the UE is registered to both the first cellular network and the second cellular network;
transmitting, to the first RAN, a first indication of a UE capability for communicating with the first RAN over a first RAT; and
based on whether the UE supports communicating over a second RAT, which is different from the first RAT, while registered to both the first cellular network and the second cellular network, either:
(i) transmitting, to the first RAN, a second indication of a UE capability for communicating over the second RAT; or
(ii) disabling UE capabilities dedicated to communicating over the second RAT.
2 . The method of claim 1 , wherein:
the UE supports communicating over the second RAT while registered to both the first cellular network and the second cellular network; and
the UE transmits the second indication.
3 . The method of claim 2 , wherein the UE transmits the first indication and the second indication in a single message.
4 . The method of claim 3 , wherein transmitting the single message includes:
transmitting an information element for reporting capabilities related to the second RAT, the information element including the first indication and the second indication.
5 . The method of claim 4 , wherein transmitting the information element includes:
transmitting the information element in response to a request from the first RAN to provide UE capability information related to communicating over the second RAT.
6 . The method of claim 4 , further comprising:
receiving, subsequently to transmitting the single message, a request from the first RAN for UE capability information related to communicating with the first RAN over the first RAT; and
transmitting, to the first RAN, a third indication of an additional UE capability for communicating with the first RAN over the first RAT.
7 . The method of claim 4 , wherein the first RAN is a more advanced RAN than the second RAN.
8 . The method of claim 3 , wherein transmitting the single message includes:
transmitting an information element for reporting capabilities related to the first RAT, the information element including the first indication and the second indication.
9 . The method of claim 8 , wherein transmitting the information element includes:
transmitting the information element in response to a request from the first RAN to provide UE capability information related to communicating with the first RAN over the first RAT.
10 . The method of claim 8 , further comprising:
receiving, subsequently to transmitting the single message, a request from the first RAN for UE capability information related to communicating with the first RAN over the second RAT; and
transmitting, to the first RAN, a third indication of an additional UE capability for communicating with the first RAN over the second RAT.
11 . The method of claim 8 , wherein the first RAN is a less advanced RAN than the second RAN.
12 . The method of claim 3 , wherein transmitting the single message
includes at least one of:
transmitting a message formatted in accordance with a protocol for controlling radio resources; or
transmitting, to the first cellular network via the first RAN, a non-access stratum (NAS) message including a capability identifier that indicates the UE capability for communicating with the first RAN over the first RAT and the UE capability for communicating with the first RAN over the second RAT.
13 . The method of claim 2 , wherein transmitting the first indication and the second indication includes:
based on at least one of (i) a home public land public network (PLMN) identifier included in the first USIM, (ii) the first cellular network, or (iii) a mobile country code of the first cellular network, identifying the UE capability for communicating with the first RAN over the first RAT and the UE capability for communicating with the first RAN over the second RAT.
14 . The method of claim 2 , further comprising:
transmitting, by the processing hardware to the second RAN, an indication of a UE capability for communicating with the second RAN over at least one of the first RAT or the second RAT.
15 . The method of claim 2 , further comprising:
transmitting, to the second RAN, an indication of a UE capability for communicating with the second RAN over the first RAT and a UE capability for communicating with the second RAN over the second RAT.
16 . The method of claim 15 , wherein at least one of:
the UE capability for communicating with the second RAN over the first RAT is different from the UE capability for communicating with the first RAN over the first RAT; or
the UE capability for communicating with the second RAN over the second RAT is different from the UE capability for communicating with the first RAN over the second RAT.
17 . The method of claim 1 , wherein:
the UE does not support communicating over the second RAT while registered to both the first cellular network and the second cellular network; and
the UE disables the UE capabilities dedicated to communicating over the second RAT.
18 . The method of claim 1 , wherein the second RAT is a more advanced RAT than the first RAT.
19 . A user equipment (UE) comprising:
processing hardware;
a first universal subscriber identity module (USIM) for communicating with a first cellular network that includes a first radio access network (RAN) and a first core network (CN);
a second USIM for communicating with a second cellular network that includes a second RAN and a second CN different from the first CN;
the UE configured to manage UE capability information by:
registering with the first cellular network via the first RAN using the first USIM,
registering with the second cellular network via the second RAN using the second USIM, so that the UE is registered to both the first cellular network and the second cellular network;
transmitting, to the first RAN, a first indication of a UE capability for communicating with the first RAN over a first RAT, and
based on whether the UE supports communicating over a second RAT, which is different from the first RAT, while registered to both the first cellular network and the second cellular network, either:
(i) transmitting, to the first RAN, a second indication of a UE capability for communicating over the second RAT; or
(ii) disabling UE capabilities dedicated to communicating over the second RAT.
20 . The UE of claim 19 , wherein:
the UE supports communicating over the second RAT while registered to both the first cellular network and the second cellular network; and
the UE transmits the second indication.