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US 11,310,700 B2Granted
Delayed radio domain fallback
AssigneeT-Mobile USA, Inc.
InventorsMing Shan Kwok, Hsin-Fu Henry Chiang, Jun Liu
Life of this patent
Estimating the term…
Abstract
A fifth generation (5G) radio access network (RAN) can determine that a user equipment (UE) should fall back to engaging in a communication session over an LTE-based Evolved Packet System (EPS) instead of a 5G system. However, to avoid interrupting setup operations that may be occurring separately for that communication session in an IP Multimedia Subsystem (IMS) apart from the 5G system, the EPS fallback can be delayed such that setup in the IMS can proceed at least to a point at which IMS signaling messages are less likely to be undeliverable due to the EPS fallback.
Claims20
A method comprising:
- determining, by a base station of a fifth generation (5G) radio access network (RAN), that a user equipment (UE) should fall back to an Evolved Packet System (EPS) to engage in a communication session that is being set up for the UE through an Internet Protocol Multimedia Subsystem (IMS);
- running, by the base station, a timer initialized to a predetermined starting value upon determining that the UE should fall back to the EPS, the predetermined starting value of the timer being at least an average period of time for the UE to reach an alerting phase during set of the communication session through the IMS;
- delaying, by the base station, sending an instruction to the UE to perform the fall back to the EPS based on a determination that an EPS fallback trigger has not yet been met while the timer is running;
- receiving, by the base station, an IMS status message from the UE indicating that the UE is not currently expecting a response message for setup of the communication session from the IMS;
- determining, by the base station, that the EPS fallback trigger has been met when the timer expires;
- and
- sending, by the base station, the instruction to the UE to perform the fall back to the EPS following the determination that the EPS fallback trigger has been met.
4 more elements
A base station of a fifth generation (5G) radio access network (RAN), comprising:
- one or more processors;
- and
- memory storing computer-executable instructions that, when executed by the one or more processors, cause the base station to perform operations comprising:
- determining that a user equipment (UE) should fall back to an Evolved Packet System (EPS) to engage in a communication session that is being set up for the UE through an Internet Protocol Multimedia Subsystem (IMS);
- running, by the base station, a timer initialized to a predetermined starting value upon determining that the UE should fall back to the EPS, the predetermined starting value of the timer being at least an average period of time for the UE to reach an alerting phase during set of the communication session through the IMS;
- delaying sending an instruction to the UE to perform the fall back to the EPS based on a determination that an EPS fallback trigger has not yet been met while the timer is running;
- receiving an IMS status message from the UE indicating that the UE is not currently expecting a response message for setup of the communication session from the IMS;
- determining that the EPS fallback trigger has been met when the timer expires;
- and
- sending the instruction to the UE to perform the fall back to the EPS following the determination that the EPS fallback trigger has been met.
7 more elements
A method comprising:
- receiving, by a user equipment (UE), an instruction from a fifth generation (5G) radio access network (RAN) to fall back to an Evolved Packet System (EPS) to engage in a communication session that is being set up for the UE through an Internet Protocol Multimedia Subsystem (IMS);
- delaying, by the UE, following the instruction to fall back to the EPS based on a determination that an EPS fallback trigger has not yet been met;
- determining, by the UE, that the EPS fallback trigger has been met, wherein the UE determines that the EPS fallback trigger has been met upon the UE reaching an alerting phase indicating that a terminal UE is ringing, wherein the alerting phase is reached when the UE receives a “180 Ringing” message from the IMS following the UE sending a call invite message;
- and
- attaching, by the UE, to the EPS following the determination that the EPS fallback trigger has been met.
2 more elements
Dependencies are inferred from the claim text.