Data transmission in an inactive state

1 . A method for wireless communication, comprising:

performing, by a terminal, a user data transmission with a network node while the terminal is in an inactive state, wherein the terminal starts an inactive data transmission timer upon initiation of the user data transmission in the inactive state;

determining, by the terminal, a failure of the user data transmission with the network node while the terminal is in the inactive state;

storing, by the terminal, a set of information about the failure of the user data transmission with the network node; and

transmitting, by the terminal, the set of information about the failure of the user data transmission with the network node to the network node or another network node.

2 . The method of claim 1 , wherein the set of information about the failure of the user data transmission includes at least one of:

(1) a failure cause for the failure of the user data transmission, wherein the failure cause includes any of: a maximum number of radio link control (RLC) re-transmissions, an expiration of a t310 timer, a beam failure recovery failure, a random access failure with a random access purpose of the user data transmission in a radio resource control (RRC) inactive state, a configured grant (CG) based failure, an out of coverage failure, an expiration of a t319 timer, an expiration of an inactive data transmission timer, or an expiration of a CG response check timer;

(2) a current buffered data size, wherein the current buffered data size is per terminal, per DRB, per logical channel, or per logical channel group; or

(3) whether a Timing Advance (TA) is valid.

3 . The method of claim 1 , wherein the set of information about the failure of the user data transmission is stored by the terminal in any of a Connection Establishment Failure (CEF) report or a Radio Link Failure (RLF) report.

4 . The method of claim 1 , wherein the set of information about the failure of the user data transmission is included in an inactive data transmission failure report sent to the network node in an inactive data transmission failure report response message, the method further comprising:

transmitting, by the terminal, an inactive data transmission failure report available indication to the network node, wherein the inactive data transmission failure report available indication is included in any of a RRCResumeComplete message, a RRCReestablishmentComplete message, a RRCReconfigurationComplete message, or a RRCSetupComplete message;

receiving, by the terminal, an inactive data transmission failure report request from the network node responsive to transmission of the inactive data transmission failure report available indication, wherein the inactive data transmission failure report request is included in a UEInformationRequest message; and

transmitting, by the terminal, an inactive data transmission failure report response to the network node responsive to receiving of the inactive data transmission failure report request, wherein the inactive data transmission failure report response is included in a UEInformationResponse message.

5 . The method of claim 1 , further comprising:

deriving, by the terminal, a first statistic relating to the user data transmission, the first statistic including any of: an uplink data throughput for the terminal, a downlink data throughput for the terminal, an uplink Uu interface delay for the terminal, a downlink Uu interface delay for the terminal, an uplink data throughput for a 5G QoS Identifier (5QI), a downlink data throughput for the 5QI, an uplink Uu interface delay for the 5QI, or a downlink Uu interface delay for the 5QI.

6 . The method of claim 5 , wherein the network node is configured to derive a second statistic that includes any of an uplink data throughput for a cell, a downlink data throughput for the cell, an uplink Uu interface delay for the cell, or a downlink Uu interface delay for the cell, and wherein the network node is configured to determine any of: whether the user data transmission is allowed for the terminal based on the first statistic and/or the second statistic, whether the user data transmission in an RRC inactive state is allowed for a data service type or a quality of service (QoS) flow based on the first statistic relating to the 5QI, or whether the user data transmission in the RRC inactive state is allowed for a cell based on the second statistic.

7 . The method of claim 1 , further comprising:

initiating, by the terminal, a CG response check timer responsive to the user data transmission to the network node, wherein the CG response check timer is stopped upon receiving a feedback from the network node, and wherein the terminal is configured to determine the user data transmission to the network node as a failed transmission responsive to an expiry of the CG response check timer.

8 . The method of claim 1 , further comprising:

initiating, by the terminal, an out of coverage timer when the terminal is in an inactive state and out of coverage of the network node, and the terminal is to initiate the user data transmission, the terminal initiates the user data transmission responsive to determining that the terminal is in coverage of the network node prior to the out of coverage timer expiring.

9 . The method of claim 1 , further comprising:

resetting, by the terminal, the inactive data transmission timer to a value of an out of coverage timer responsive to determining that the terminal is out of coverage of the network node and the user data transmission is ongoing and a remaining time of the inactive data transmission timer is less than the value of the out of coverage timer.

10 . The method of claim 1 , wherein the set of information about the failure of the user data transmission is stored by the terminal in a random-access report.

11 . An apparatus for wireless communication comprising processor electronics that is configured to:

perform a user data transmission with a network node while the apparatus is in an inactive state, wherein the apparatus starts an inactive data transmission timer upon initiation of the user data transmission in the inactive state;

determine a failure of the user data transmission with the network node while the apparatus is in the inactive state;

store a set of information about the failure of the user data transmission with the network node; and

transmit the set of information about the failure of the user data transmission with the network node to the network node or another network node.

12 . The apparatus of claim 11 , wherein the set of information about the failure of the user data transmission includes at least one of:

(1) a failure cause for the failure of the user data transmission, wherein the failure cause includes any of: a maximum number of radio link control (RLC) re-transmissions, an expiration of a t310 timer, a beam failure recovery failure, a random access failure with a random access purpose of the user data transmission in a radio resource control (RRC) inactive state, a configured grant (CG) based failure, an out of coverage failure, an expiration of a t319 timer, an expiration of an inactive data transmission timer, or an expiration of a CG response check timer;

(2) a current buffered data size, wherein the current buffered data size is per apparatus, per DRB, per logical channel, or per logical channel group; or

(3) whether a Timing Advance (TA) is valid.

13 . The apparatus of claim 11 , wherein the set of information about the failure of the user data transmission is stored by the apparatus in any of a Connection Establishment Failure (CEF) report or a Radio Link Failure (RLF) report.

14 . The apparatus of claim 11 , wherein the set of information about the failure of the user data transmission is included in an inactive data transmission failure report sent to the network node in an inactive data transmission failure report response message, wherein the processor electronics is further configured to:

transmit an inactive data transmission failure report available indication to the network node, wherein the inactive data transmission failure report available indication is included in any of a RRCResumeComplete message, a RRCReestablishmentComplete message, a RRCReconfigurationComplete message, or a RRCSetupComplete message;

receive an inactive data transmission failure report request from the network node responsive to transmission of the inactive data transmission failure report available indication, wherein the inactive data transmission failure report request is included in a UEInformationRequest message; and

transmit an inactive data transmission failure report response to the network node responsive to receiving of the inactive data transmission failure report request, wherein the inactive data transmission failure report response is included in a UEInformationResponse message.

15 . The apparatus of claim 11 , wherein the processor electronics is configured to:

derive a first statistic relating to the user data transmission, the first statistic including any of: an uplink data throughput for the apparatus, a downlink data throughput for the apparatus, an uplink Uu interface delay for the apparatus, a downlink Uu interface delay for the apparatus, an uplink data throughput for a 5G QoS Identifier (5QI), a downlink data throughput for the 5QI, an uplink Uu interface delay for the 5QI, or a downlink Uu interface delay for the 5QI.

16 . The apparatus of claim 15 , wherein the network node is configured to derive a second statistic that includes any of an uplink data throughput for a cell, a downlink data throughput for the cell, an uplink Uu interface delay for the cell, or a downlink Uu interface delay for the cell, and wherein the network node is configured to determine any of: whether the user data transmission is allowed for the apparatus based on the first statistic and/or the second statistic, whether the user data transmission in an RRC inactive state is allowed for a data service type or a quality of service (QoS) flow based on the first statistic relating to the 5QI, or whether the user data transmission in the RRC inactive state is allowed for a cell based on the second statistic.

17 . The apparatus of claim 11 , wherein the processor electronics is configured to:

initiate a CG response check timer responsive to the user data transmission to the network node, wherein the CG response check timer is stopped upon receiving a feedback from the network node, and wherein the apparatus is configured to determine the user data transmission to the network node as a failed transmission responsive to an expiry of the CG response check timer.

18 . The apparatus of claim 11 , wherein the processor electronics is configured to:

initiate an out of coverage timer when the apparatus is in an inactive state and out of coverage of the network node, and the apparatus is to initiate the user data transmission, the apparatus initiates the user data transmission responsive to determining that the apparatus is in coverage of the network node prior to the out of coverage timer expiring.

19 . The apparatus of claim 11 , wherein the processor electronics is configured to:

reset the inactive data transmission timer to a value of an out of coverage timer responsive to determining that the apparatus is out of coverage of the network node and the user data transmission is ongoing and a remaining time of the inactive data transmission timer is less than the value of the out of coverage timer.

20 . The apparatus of claim 11 , wherein the set of information about the failure of the user data transmission is stored by the apparatus in a random-access report.