Mobility state-based SDT procedures
Systems and methods for small data transmissions (SDTs) between a user equipment (UE) and a network are disclosed herein. In some embodiments, the UE determines whether to perform an SDT procedure by comparing its own mobility state to an SDT mobility state condition provided by the network. The UE may also determine whether to perform the SDT procedure by comparing the size of user plane (UP) data to be sent with the SDT procedure to an SDT mobility-based data amount threshold provided by the network. Upon entering an RRC_INACTIVE state, the UE may start a validity timer relative to any such SDT mobility state condition and/or SDT mobility-based data amount threshold, and invalidate these once the validity timer expires. In some disclosed embodiments, the UE reports its determined mobility state to the network during an SDT procedure so that the network can accordingly select configuration parameters for SDT procedures.
1. A method of a user equipment (UE), comprising:
receiving, from a wireless network, a small data transmission (SDT) mobility state condition;
determining a mobility state of the UE;
determining that an SDT procedure can be triggered with the wireless network based on a comparison of the SDT mobility state condition and the mobility state of the UE;
triggering the SDT procedure with the wireless network; and
reporting, to the wireless network, the mobility state of the UE in the SDT procedure with the wireless network, wherein the reporting of the mobility state of the UE occurs via a use of a medium access control (MAC) control element (CE) after a successful initial access of the SDT procedure.
2. The method of claim 1 , further comprising:
starting a condition validity timer corresponding to a condition validity period for the SDT mobility state condition; and
invalidating the SDT mobility state condition upon expiration of the condition validity timer.
3. The method of claim 2 , wherein a duration of the condition validity timer is configured according to a condition validity timer configuration received from the wireless network.
4. The method of claim 1 , further comprising:
receiving, from the wireless network, an SDT mobility-based data amount threshold; and
determining an amount of data to be sent to the network in the SDT procedure;
wherein the determining that the SDT procedure can be triggered with the wireless network is further based on the SDT mobility-based data amount threshold and the amount of data to be sent to the network in the SDT procedure.
5. The method of claim 4 , further comprising:
starting a condition validity timer corresponding to a condition validity period for the SDT mobility state condition and the SDT mobility-based data amount threshold; and
invalidating the SDT mobility state condition and the SDT mobility state condition upon expiration of the condition validity timer.
6. The method of claim 1 , wherein the UE determines that that the SDT procedure can be triggered with the wireless network when the mobility state of the UE is lower than or equal to the SDT mobility state condition.
7. The method of claim 1 , wherein the SDT mobility state condition is one of a High-mobility state, a Medium-mobility state, and a Normal-mobility state.
8. The method of claim 1 , wherein the SDT mobility state condition is received from the wireless network in an RRCRelease with Suspendconfig message.
9. The method of claim 8 , wherein the RRCRelease with Suspendconfig message is other than a most recent RRCRelease with Suspendconfig message received from the wireless network.
10. The method of claim 1 , wherein the SDT mobility state condition is received at the UE via dedicated signaling from a base station of the wireless network.
11. The method of claim 1 , wherein the SDT mobility state condition is received at the UE via broadcast signaling in a system information block (SIB) from a base station of the wireless network.
12. A method of a user equipment (UE), comprising:
receiving, from a wireless network, an RRCRelease with Suspendconfig message;
entering an RRC_INACTIVE state in response to receiving the RRCRelease with Suspendconfig message;
determining a mobility state of the UE;
initiating, with the wireless network, a small data transmission (SDT) procedure in response to an arrival of data for an SDT data radio bearer (SDT-DRB) of the SDT procedure and a determination that the SDT procedure can be triggered based on a comparison of a SDT mobility state condition and the mobility state of the UE; and
reporting, to the wireless network, the mobility state of the UE in the SDT procedure with the wireless network, wherein the reporting of the mobility state of the UE occurs via a use of a medium access control (MAC) control element (CE) after a successful initial access of the SDT procedure.
13. The method of claim 12 , wherein the reporting of the mobility state of the UE is performed according to RRC signaling previously received at the UE from the wireless network.
14. A method of a wireless network, comprising:
receiving, from a user equipment (UE), a mobility state of the UE during a small data transmission (SDT) procedure with the UE for pending SDT data at the UE, wherein the mobility state of the UE is received via a use of a medium access control (MAC) control element (CE) after a successful initial access of the SDT procedure;
determining one or more configuration parameters for the SDT procedure with the UE based on the mobility state of the UE; and
performing, with the UE, the SDT procedure according to the one or more configuration parameters.
15. The method of claim 14 , wherein the one or more configuration parameters indicates an SDT mobility state condition to send to the UE as part of the SDT procedure.
16. The method of claim 14 , wherein the one or more configuration parameters indicates a maximum lifespan for any configured grants provided to the UE to use during the SDT procedure.
17. The method of claim 14 , wherein the one or more configuration parameters indicates a maximum duration to allow the UE to operate within the SDT procedure.