User equipment having multiple subscriber identity modules with improved suspend / resume operation
Devices and associated methods for operating a dual-subscriber identity module (SIM) dual-standby (DSDS) user equipment device (UE) configured with a first SIM and a second SIM. The UE performs communications with a first cellular network using the first SIM and a first radio resource control (RRC) connection, and receives a request to perform a higher priority communication using the second SIM. In response to the request to perform the higher priority communication, the UE transmits a request to the first network to suspend the first RRC connection. After transmission of the request to suspend the first RRC connection, the UE receives a message from the first network to place the first RRC connection in an inactive state, and initiates a timer, wherein the timer is used to determine whether the first RRC connection remains in the inactive state or transitions to an idle state.
1. An apparatus, comprising:
a processor configured to cause a user equipment device (UE) to:
perform cellular data communications with a first cellular network using a first subscriber identity module (SIM) of the UE and a first radio resource control (RRC) connection in a first RRC State associated with the first SIM;
determine that communication activity prompts use of a second SIM of the UE, wherein determining that communication activity prompts use of the second SIM comprises determining a paging message is received in the UE;
in response to determination that the communication activity prompts use of the second SIM, transmit a message to the first cellular network while cellular data communications are being performed with the first RRC connection using the first SIM that requests release of the first RRC connection; and
subsequent to transmitting the message to the first cellular network, release the first RRC connection and change RRC State associated with the first SIM from the first RRC State to a second RRC State.
2. The apparatus of claim 1 ,
wherein one or more of the first and second SIMs is an embedded SIM using embedded memory in the UE to store subscriber information related to the one or more of the first and second SIM.
3. The apparatus of claim 1 ,
wherein the use of the second SIM comprises a higher priority use than the cellular data communications.
4. The apparatus of claim 3 ,
wherein the paging message is received from a second cellular network for the second SIM.
5. The apparatus of claim 1 ,
wherein the first RRC State is an RRC_Connected State.
6. The apparatus of claim 1 ,
wherein the UE is further configured to:
transition an RRC State associated with the second SIM from a third RRC State to a fourth RRC State,
wherein the third RRC State is one of an RRC_Idle State or an RRC_Inactive State, and
wherein the fourth RRC State is an RRC_Connected State.
7. The apparatus of claim 1 ,
wherein the second RRC State is one of an RRC_Idle State or an RRC Inactive State.
8. A method, comprising, by a user equipment device (UE):
performing cellular data communications with a first cellular network using a first subscriber identity module (SIM) of the UE and a first radio resource control (RRC) connection in a first RRC State associated with the first SIM;
determining that communication activity prompts use of a second SIM of the UE, wherein determining that communication activity prompts use of the second SIM comprises determining a paging message is received in the UE;
in response to determination that the communication activity prompts use of the second SIM, transmitting a message to the first cellular network while the cellular data communications are being performed with the first RRC connection using the first SIM, the message requesting release of the first RRC connection; and
subsequent to transmitting the message to the first cellular network, releasing the first RRC connection and changing RRC State associated with the first SIM from the first RRC State to a second RRC State.
9. The method of claim 8 ,
wherein one or more of the first and second SIMs is an embedded SIM using embedded memory in the UE to store subscriber information related to the one or more of the first and second SIMs.
10. The method of claim 8 ,
wherein the use of the second SIM comprises a higher priority use than the cellular data communications.
11. The method of claim 10 ,
wherein the paging message is received from a second cellular network for the second SIM.
12. The method of claim 8 ,
wherein the first RRC State is an RRC_Connected State.
13. The method of claim 8 ,
wherein the second RRC State is one of an RRC_Idle State or an RRC_Inactive State.
14. The method of claim 8 , further comprising:
transitioning an RRC State associated with the second SIM from a third RRC State to a fourth RRC State,
wherein the third RRC State is one of an RRC Idle State or an RRC_Inactive State, and
wherein the fourth RRC State is an RRC_Connected State.
15. An apparatus, comprising:
a processor configured to cause an access and mobility management function (AMF) to:
using a first cellular network, manage cellular data communications corresponding to a first radio resource control (RRC) connection with a user equipment device (UE) that is using a first subscriber identity module (SIM) of the UE, wherein the UE is in a first RRC State associated with the first SIM;
receive a message from the UE requesting release of the first RRC connection and requesting suspension of paging for the UE associated with the first cellular network while cellular data communications are being performed with the first RRC connection using the first SIM, wherein the message is received responsive to a determination that communication activity prompts use of a second SIM of the UE, wherein determining that communication activity prompts use of the second SIM comprises determining a paging message is received in the UE; and
subsequent to receiving the message from the UE, suspend paging associated with the UE, release the first RRC connection and change RRC State associated with the first SIM from the first RRC State to a second RRC State.
16. The apparatus of claim 15 ,
wherein the AMF manages cellular data communications with the UE through a g Node B (gNB).
17. The apparatus of claim 15 ,
wherein the use of the second SIM comprises a higher priority use than the cellular data communications.
18. The apparatus of claim 15 ,
wherein the first RRC State is an RRC_Connected State.
19. The apparatus of claim 15 ,
wherein the second RRC State is one of an RRC_Idle State or an RRC Inactive State.