RRC RELEASE AFTER SMALL DATA TRANSMISSION COMPLETION
A wireless device receives a radio resource control (RRC) message comprising configuration parameters for uplink resources associated with a small data transmission (SDT) procedure of the wireless device. The wireless device transmits, to a base station central unit (BS-CU) via the uplink resources of a base station distributed unit (BS-DU), an RRC resume request message for the SDT procedure, and uplink data associated with the SDT procedure. The wireless device receives, from the BS-CU to via the BS-DU, an RRC release message after the BS-CU receives a message indicating inactivity notification and completion of the SDT procedure.
1 . A baseband processing unit for a base station central unit control plane (CU-CP), comprising:
one or more processors configured to:
receive a radio resource control (RRC) resume request message for a small data transmission (SDT) procedure of a wireless device;
receive an indication message indicating an inactivity notification; and
in response to receiving the indication message, send a release message based on the indication message.
2 . The baseband processing unit of claim 1 , wherein the RRC resume request message is received by the base station CU-CP from the wireless device via a base station distributed unit (DU), wherein the base station CU-CP receives the indication message from the base station DU, wherein the base station CU-CP sends the release message to the base station CU-CP, and wherein the indication message comprises an information element indicating a size of downlink data to transmit to the wireless device.
3 . The baseband processing unit of claim 1 , wherein the indication message further indicates a completion of the SDT procedure, and wherein the one or more processors are further configured to:
send the release message based on the completion of the SDT procedure; and
initiate a release procedure based on the completion of the SDT procedure.
4 . The baseband processing unit of claim 1 , wherein the release message comprises an indication that the wireless device stays in an RRC inactive state or an RRC idle state.
5 . The baseband processing unit of claim 1 , wherein the release message comprises configuration parameters for suspension of an RRC connection.
6 . The baseband processing unit of claim 1 , wherein to send the release message comprises to send the release message within a context release command message.
7 . The baseband processing unit of claim 1 , wherein the indication message comprises an indication of a completion of the SDT procedure and a bearer identifier of a bearer associated with the completion of the SDT procedure.
8 . The baseband processing unit of claim 1 , wherein the SDT procedure comprises one or more of:
an initial uplink data transmission;
an initial downlink data transmission; and
at least one subsequent data transmission.
9 . A baseband processing unit for a base station distributed unit (DU), comprising:
one or more processors configured to:
send a radio resource control (RRC) resume request message for a small data transmission (SDT) procedure of a wireless device;
send an indication message indicating an inactivity notification; and
in response to sending the indication message, receive a release message.
10 . The baseband processing unit of claim 9 , wherein the one or more processors are further configured to:
receive a context release command message from a base station central unit control plane (CU-CP)indicating releasing an RRC connection of the wireless device, wherein the context release command message comprises an RRC release message associated with the wireless device, and wherein the base station DU sends the RRC resume request message and the indication message to the base station CU-CP, and wherein the base station DU receives the release message from the base station CU-CP; and
send, to the wireless device, the RRC release message.
11 . The baseband processing unit of claim 10 , wherein the RRC release message comprises an indication that the wireless device is in an RRC inactive state or an RRC idle state.
12 . The baseband processing unit of claim 10 , wherein the RRC release message comprises configuration parameters for suspension of the RRC connection.
13 . The baseband processing unit of claim 9 , wherein the one or more processors are further configured to receive the RRC resume request message from the wireless device, and wherein the indication message comprises an information element indicating a size of downlink data to transmit to the wireless device.
14 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause a base station central unit control plane (CU-CP) to:
receive a radio resource control (RRC) resume request message for a small data transmission (SDT) procedure of a wireless device;
receive an indication message indicating an inactivity notification; and
in response to receiving the indication message, send a release message based on the indication message.
15 . The baseband processing unit of claim 1 , wherein the RRC resume request message is received by the base station CU-CP from the wireless device via a base station distributed unit (DU), wherein the base station CU-CP receives the indication message from the base station DU, wherein the base station CU-CP sends the release message to the base station CU-CP, and wherein the indication message comprises an information element indicating a size of downlink data to transmit to the wireless device.
16 . The non-transitory computer-readable medium of claim 14 , wherein the indication message further indicates a completion of the SDT procedure, and wherein the instructions that, when executed by one or more processors, cause the base station CU-CP to:
send the release message based on the completion of the SDT procedure; and
initiate a release procedure based on the completion of the SDT procedure.
17 . The non-transitory computer-readable medium of claim 14 , wherein the release message comprises an indication that the wireless device stays in an RRC inactive state or an RRC idle state.
18 . The non-transitory computer-readable medium of claim 14 , wherein the release message comprises configuration parameters for suspension of an RRC connection.
19 . The non-transitory computer-readable medium of claim 14 , wherein to send the release message comprises to send the release message within a context release command message.
20 . The non-transitory computer-readable medium of claim 14 , wherein the indication message comprises an indication of a completion of the SDT procedure and a bearer identifier of a bearer associated with the completion of the SDT procedure.