Data handling during SDT
Embodiments of the present disclosure relate to handling data during SDT. A first device in an inactive state performs an initial transmission to a second device during an SDT. The first device receives, from the second device, data subsequent to the initial transmission during the SDT. The first device buffers the data. The first device handles the buffered data in accordance with a determination that security verification is successful.
1 . A first device, comprising:
at least one processor; and
at least one memory comprising computer-executable instructions that, when executed by the
at least one processor, cause the first device to perform the following operations:
performing an initial transmission comprising a packet data convergence protocol (PDCP) service data unit (SDU) in a message 3 (MSG3) of a four-step random access (RA) procedure to a second device that is a next generation NodeB (gNB) during a small data transmission procedure;
receiving, from the second device on a data radio bearer (DRB1) for which security verification is disabled, data subsequent to the initial transmission during the small data transmission procedure, wherein the DRB1 comprises one of the following: a data radio bearer or a signaling radio bearer;
receiving, from the second device, additional data on a second data radio bearer (DRB2) that is different from the DRB1, the second radio bearer being configured with security verification;
confirming the second device is genuine based on the security verification of the further data;
based on the confirming, buffering the data at a radio link control (RLC) layer of the first device;
determining that integrity protection verification and ciphering verification of access stratum (AS) security parameters are successful based on receipt of a radio resource control (RRC) release message indicating maintenance of the RRC inactive state; and
based on the determination that integrity protection verification and ciphering verification of the AS security parameters are successful based on receipt of the RRC release message indicating maintenance of the RRC inactive state, handling the buffered data by forwarding the buffered data from the RLC layer to a packet data convergence protocol (PDCP) layer of the first device, the PDCP layer providing an indication to the RLC layer based on verification being successful.
2 . The first device of claim 1 , wherein the request comprises a radio resource control resume request for small data transmission, and the response comprises a radio resource control message.
3 . The first device of claim 2 , wherein the data received on the DRB1 is segmented across multiple transport blocks based on the PDCP service data unit (SDU) being too large to fit into one transport block.
4 . The first device of claim 3 , wherein the first device is a terminal device.
5 . A system comprising:
a first device;
at least one processor; and
at least one memory comprising computer-executable instructions that, when executed by the at least one processor, cause the first device to perform the following operations:
performing an initial transmission comprising a packet data convergence protocol (PDCP) service data unit (SDU) in a message 3 (MSG3) of a four-step random access (RA) procedure to a second device that is a next generation NodeB (gNB) during a small data transmission procedure;
receiving, from the second device on a data radio bearer (DRB1) for which security verification is disabled, data subsequent to the initial transmission during the small data transmission procedure, wherein the DRB1 comprises one of the following: a data radio bearer or a signaling radio bearer;
receiving, from the second device, additional data on a second data radio bearer (DRB2) that is different from the DRB1, the second radio bearer being configured with security verification;
confirming the second device is genuine based on the security verification of the further data;
based on the confirming, buffering the data at a radio link control (RLC) layer of the first device;
determining that integrity protection verification and ciphering verification of access stratum (AS) security parameters are successful based on receipt of a radio resource control (RRC) release message indicating maintenance of the RRC inactive state; and
based on the determination that integrity protection verification and ciphering verification of the AS security parameters are successful based on receipt of the RRC release message indicating maintenance of the RRC inactive state, handling the buffered data by forwarding the buffered data from the RLC layer to a packet data convergence protocol (PDCP) layer of the first device, the PDCP layer providing an indication to the RLC layer based on verification being successful.
6 . The system of claim 5 , wherein the request comprises a radio resource control resume request for small data transmission, and the response comprises a radio resource control message.
7 . The system of claim 6 , wherein the data received on the DRB1 is segmented across multiple transport blocks based on the PDCP service data unit (SDU) being too large to fit into one transport block.
8 . The system of claim 7 , wherein the first device is a terminal device.
9 . A method performed by a first device, the method comprising:
performing an initial transmission comprising a packet data convergence protocol (PDCP) service data unit (SDU) in a message 3 (MSG3) of a four-step random access (RA) procedure to a second device that is a next generation NodeB (gNB) during a small data transmission procedure;
receiving, from the second device on a data radio bearer (DRB1) for which security verification is disabled, data subsequent to the initial transmission during the small data transmission procedure, wherein the DRB1 comprises one of the following: a data radio bearer or a signaling radio bearer;
receiving, from the second device, additional data on a second data radio bearer (DRB2) that is different from the DRB1, the second radio bearer being configured with security verification;
confirming the second device is genuine based on the security verification of the further data;
based on the confirming, buffering the data at a radio link control (RLC) layer of the first device;
determining that integrity protection verification and ciphering verification of access stratum (AS) security parameters are successful based on receipt of a radio resource control (RRC) release message indicating maintenance of the RRC inactive state; and
based on the determination that integrity protection verification and ciphering verification of the AS security parameters are successful based on receipt of the RRC release message indicating maintenance of the RRC inactive state, handling the buffered data by forwarding the buffered data from the RLC layer to a packet data convergence protocol (PDCP) layer of the first device, the PDCP layer providing an indication to the RLC layer based on verification being successful.
10 . The method 9 , wherein the request comprises a radio resource control resume request for small data transmission, and the response comprises a radio resource control message.
11 . The method of claim 10 , wherein the data received on the DRB1 is segmented across multiple transport blocks based on the PDCP service data unit (SDU) being too large to fit into one transport block.