Method and apparatus for supporting UP security for MO-EDT in CU-DU split in a wireless communication system
A method and apparatus supporting UP security for MO-EDT in CU-DU split in a wireless communication system. A central unit (CU) receives, from a distributed unit (DU), a first message including a PDCP Data PDU, wherein the PDCP Data PDU is configured by a wireless device. A CU calculates a HASH DATA from the PDCP Data PDU. A CU verifies a Short MAC-I of the wireless device based on the HASH DATA . A CU transmits, to the DU, a second message to setup a UE context for the wireless device in the DU based on the verification.
1. A method performed by a central unit (CU) in a wireless communication system, the method comprising:
receiving, from a distributed unit (DU), a first message including a Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU), wherein the PDCP PDU is configured by a wireless device, and
wherein the first message includes a Resume identity (ID) or an inactive-radio network temporary identity (I-RNTI) for the wireless device;
calculating a HASH DATA from the PDCP PDU;
triggering a Retrieve UE Context procedure with the HASH DATA based on that the CU does not have a UE context for the Resume ID or the I-RNTI;
verifying a Short MAC-I of the wireless device based on (i) the HASH DATA and (ii) the UE context for the Resume ID or the I-RNTI; and
transmitting, to the DU, a second message to setup the UE context for the wireless device in the DU based on the verification.
2. The method of claim 1 , wherein the UE context for the Resume ID or the I-RNTI includes at least one of a source cell-radio network temporary identity (C_RNTI), source physical cell identity (PCI), resume constant, and/or target Cell-ID.
3. The method of claim 1 , wherein the first message is a W1AP INITIAL UL RRC MESSAGE TRANSFER message.
4. The method of claim 1 , wherein the second message is a W1AP UE CONTEXT SETUP REQUEST message.
5. The method of claim 1 , wherein the CU is an eNB-CU and the DU is an eNB-DU.
6. The method of claim 1 , wherein the first message is a F1AP INITIAL UL RRC MESSAGE TRANSFER message.
7. The method of claim 1 , wherein the second message is a F1AP UE CONTEXT SETUP REQUEST message.
8. The method of claim 1 , wherein the CU is a gNB-CU and the DU is a gNB-DU.
9. The method of claim 1 , wherein the wireless device is in communication with at least one of a mobile device, a network, and/or autonomous vehicles other than the wireless device.
10. A method performed by a central unit (CU)-control plane (CP) in a wireless communication system, the method comprising:
receiving, from a distributed unit (DU), a first message including a Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU), wherein the PDCP PDU is configured by a wireless device, and
wherein the first message includes a Resume identity (ID) or an inactive-radio network temporary identity (I-RNTI) for the wireless device;
calculating a HASH DATA from the PDCP PDU;
triggering a Retrieve UE Context procedure with the HASH DATA based on that the CU does not have a UE context for the Resume ID or the I-RNTI;
verifying a Short MAC-I of the wireless device based on (i) the HASH DATA and (ii) the UE context for the Resume ID or the I-RNTI; and
transmitting, to a CU-user plane (UP), a second message including the PDCP PDU.
11. The method of claim 10 , wherein the second message is an E1AP BEARER CONTEXT MODIFICATION REQUEST message.
12. The method of claim 10 , wherein the second message includes a downlink (DL) data indication,
wherein the DL data indication informs the CU-UP that DL data is pending.
13. The method of claim 12 , wherein the method further comprises:
transmitting, to the DU, a UE CONTEXT RELEASE COMMAND message to release a RRC connection with the wireless device,
wherein the UE CONTEXT RELEASE COMMAND message includes the DL data indication to inform the DU that the DL data is pending.