Header formats in wireless communication

1. A method of wireless communication at a transmitting device, comprising:

receiving one or more quality of service (QoS) flows from a protocol layer;

mapping the one or more QoS flows to one or more data radio bearers (DRBs) established between the transmitting device and a receiving device; and

transmitting a plurality of media access control (MAC) protocol data units (PDUs) corresponding to the one or more DRBs, each MAC protocol data unit (PDU) comprising:

a packet data convergence protocol (PDCP) PDU comprising a PDCP header preceding an unciphered header of a partially ciphered PDCP payload,

wherein the unciphered header includes a reflective QoS indicator (RQI) that provides a basis for setting up a mapping between a QoS flow and a DRB for an uplink (UL) transmission prior to completing a deciphering of the partially ciphered PDCP payload.

2. The method of claim 1 , wherein the PDCP payload comprises:

a service data adaptation protocol (SDAP) PDU comprising an SDAP header and an SDAP payload corresponding to the one or more DRBs, wherein the SDAP header is not ciphered.

3. The method of claim 2 , wherein the SDAP payload is ciphered.

4. The method of claim 2 , wherein the transmitting comprises:

reading the SDAP header from the partially ciphered PDCP payload to obtain prioritization information of the SDAP payload; and

prioritizing transmission of the plurality of MAC PDUs based on the prioritization information.

5. The method of claim 4 , wherein the prioritizing comprises:

prioritizing transmission of the MAC PDUs of a same logical channel based on the prioritization information of the SDAP payload in each MAC PDU.

6. The method of claim 1 , further comprising:

receiving a second MAC PDU comprising a second PDCP PDU comprising a PDCP header preceding an unciphered header of a partially ciphered PDCP payload;

extracting a second SDAP PDU corresponding to one or more second QoS flows, from the partially ciphered PDCP payload of the second PDCP PDU; and

reading an SDAP header of the second SDAP PDU to obtain information on the one or more second QoS flows prior to deciphering an SDAP payload of the second SDAP PDU.

7. The method of claim 6 , wherein the SDAP payload comprises an Internet protocol payload.

8. A method of wireless communication at a receiving device, comprising:

receiving a media access control (MAC) protocol data unit (PDU) comprising a packet data convergence protocol (PDCP) PDU comprising a PDCP header and a partially ciphered PDCP payload;

extracting a service data adaptation protocol (SDAP) PDU corresponding to one or more quality of service (QoS) flows, from the partially ciphered PDCP payload;

reading an SDAP header of the SDAP PDU to obtain information on the one or more QoS flows prior to deciphering an SDAP payload of the SDAP PDU;

determining a reflective QoS indicator (RQI) from the obtained information; and

setting up a mapping, based on the RQI, between a QoS flow and a data radio bearer (DRB) for an uplink (UL) transmission prior to completing the deciphering of the SDAP payload.

9. The method of claim 8 , wherein the extracting the SDAP PDU comprises:

deciphering the SDAP payload while not deciphering the SDAP header.

10. The method of claim 8 , wherein the SDAP payload comprises an Internet protocol payload.

11. An apparatus for wireless communication, comprising:

a memory storing executable code;

a transceiver configured for wireless communication; and

a processor communicatively coupled with the memory and the transceiver,

wherein the processor and the memory are configured to:

receive a media access control (MAC) protocol data unit (PDU) comprising a packet data convergence protocol (PDCP) PDU comprising a PDCP header and a partially ciphered PDCP payload;

extract a service data adaptation protocol (SDAP) PDU corresponding to one or more quality of service (QoS) flows from the partially ciphered PDCP payload;

read an SDAP header of the SDAP PDU to obtain information on the one or more QoS flows prior to deciphering an SDAP payload of the SDAP PDU;

determine a reflective QoS indicator (RQI) from the obtained information; and

set up a mapping, based on the RQI, between a QoS flow and a data radio bearer (DRB) for an uplink (UL) transmission prior to completing the deciphering of the SDAP payload.

12. The apparatus of claim 11 , wherein the processor and the memory are further configured to:

decipher the SDAP payload while not deciphering the SDAP header.

13. The apparatus of claim 11 , wherein the SDAP payload comprises an Internet protocol payload.