Methods and related devices for multi-connectivity
A User Equipment (UE) and a method performed by the UE for multi-connectivity are provided. The method includes receiving, from a Master Cell Group (MCG), a first Radio Resource Control (RRC) message comprising at least one Secondary Cell Group (SCG) Data Radio Bearer (DRB) configuration; starting a first timer upon receiving the first RRC message; and stopping the first timer when one of a plurality of conditions is satisfied, wherein the plurality of conditions include: transmitting an RRC reestablishment request message to the MCG; transmitting an SCG Failure Information message to the MCG before the first timer expires; and successfully adding an SCG based on the at least one SCG DRB configuration.
1. A User Equipment (UE) for multi-connectivity, the UE comprising:
a transmitter;
a receiver configured to receive, from a Master Cell Group (MCG), a first Radio Resource Control (RRC) message comprising at least one Secondary Cell Group (SCG) Data Radio Bearer (DRB) configuration;
a processor coupled to the receiver and the transmitter; and
a memory coupled to the processor, wherein the memory stores one or more computer-executable instructions that, when executed by the processor, cause the UE to:
start a first timer upon receiving the first RRC message; and
stop the first timer when at least one of a plurality of conditions is satisfied, wherein the plurality of conditions comprises:
transmitting, by the transmitter, an RRC reestablishment request message to the MCG; and
transmitting, by the transmitter, an SCG Failure Information message to the MCG before the first timer expires.
2. The UE according to claim 1 , wherein the at least one SCG DRB configuration comprises a first SCG DRB configuration and a second SCG DRB configuration, wherein the one or more computer-executable instructions, when executed by the processor, further cause the UE to:
set the first timer for the first SCG DRB configuration; and
set a second timer for the second SCG DRB configuration.
3. The UE according to claim 2 , wherein the first timer and the second timer have different values.
4. The UE according to claim 1 , wherein the one or more computer-executable instructions, when executed by the processor, further cause the UE to:
report failure information to the MCG when the first timer expires.
5. The UE according to claim 4 , wherein the one or more computer-executable instructions, when executed by the processor, further cause the UE to:
establish an MCG DRB with the MCG after reporting the failure information.
6. The UE according to claim 4 , wherein the failure information indicates at least one suitable cell determined by the UE.
7. The UE according to claim 4 , wherein the failure information indicates a reconfiguration failure of the first RRC message.
8. The UE according to claim 4 , wherein the failure information is reported via a second RRC message.
9. The UE according to claim 4 , wherein the failure information indicates at least one non-suitable cell determined by the UE.
10. The UE according to claim 4 , wherein the one or more computer-executable instructions, when executed by the processor, further cause the UE to:
perform measurements configured by the MCG after reporting the failure information.
11. A method performed by a User Equipment (UE) for multi-connectivity, the method comprising:
receiving, from a Master Cell Group (MCG), a first Radio Resource Control (RRC) message comprising at least one Secondary Cell Group (SCG) Data Radio Bearer (DRB) configuration;
starting a first timer upon receiving the first RRC message; and
stopping the first timer when at least one of a plurality of conditions is satisfied, wherein the plurality of conditions comprises:
transmitting an RRC reestablishment request message to the MCG; and
transmitting an SCG Failure Information message to the MCG before the first timer expires.
12. The method according to claim 11 , wherein the at least one SCG DRB configuration comprises a first SCG DRB configuration and a second SCG DRB configuration, the method further comprising:
setting the first timer for the first SCG DRB configuration; and
setting a second timer for the second SCG DRB configuration.
13. The method according to claim 12 , wherein the first timer and the second timer have different values.
14. The method according to claim 11 , further comprising:
reporting failure information to the MCG when the first timer expires.
15. The method according to claim 14 , further comprising:
establishing an MCG DRB with the MCG after reporting the failure information.
16. The method according to claim 14 , wherein the failure information indicates at least one suitable cell determined by the UE.
17. The method according to claim 14 , wherein the failure information indicates a reconfiguration failure of the first RRC message.
18. The method according to claim 14 , wherein the failure information is reported via a second RRC message.
19. The method according to claim 14 , wherein the failure information indicates at least one non-suitable cell determined by the UE.
20. The method according to claim 14 , further comprising:
performing measurements configured by the MCG after reporting the failure information.