Media access control header and transport block formats
Various aspects described herein relate to encoding or decoding a media access control (MAC) layer transport block having an enhanced MAC header format, a split and partial MAC header, and a MAC transport block design. A method, a computer-readable medium, and an apparatus are provided. The techniques described herein may apply to different communications technologies, including 5th Generation (5G) or New Radio (NR), wireless communications technology.
1. A method of wireless communications at a user equipment (UE), comprising:
identifying, for a media access control (MAC) header, a first portion including a first subheader corresponding to a pre-subheader at a beginning location in a MAC packet data unit (PDU) and a second portion including a second subheader corresponding to a post-subheader at an end location in the MAC PDU, the pre-subheader including information to be sent prior to information in the post-subheader, wherein the post-subheader includes information satisfying a data generation time for transmission; and
sending, from the UE to a network entity on an uplink communication channel, the first portion at a first time and the second portion at a second time after the first time.
2. The method of claim 1 , wherein a size of the pre-subheader is at least one of a fixed size known to one or both of the UE or the network entity, or a variable size indicated at the beginning of the MAC PDU.
3. The method of claim 1 , wherein the MAC PDU includes a cyclic redundancy check (CRC) according to at least one of:
on the pre-subheader,
on the first portion of the MAC PDU covering at least the pre-subheader, or
per MAC control element.
4. The method of claim 1 , wherein the post-subheader includes a header length corresponding to a backward pointer to a beginning of the MAC PDU.
5. The method of claim 1 , wherein the MAC PDU includes a cyclic redundancy check (CRC) according to at least one of:
on the post-subheader,
on the second portion of the MAC PDU covering at least the post-subheader, or
per MAC control element.
6. The method of claim 1 , further comprising receiving an acknowledgment (ACK) including at least one of a control portion or a data portion in response to sending at least the first portion at the first time.
7. The method of claim 1 , further comprising:
receiving, on a downlink communication channel from the network entity, a distinct MAC PDU including a distinct MAC header including at least two portions, the distinct MAC PDU including downlink-specific control elements in at least one of the two portions; and
transmitting, on the uplink communication channel to the network entity, an ACK including at least one of a control portion or a data portion in response to receiving the distinct MAC PDU.
8. An apparatus for wireless communication, comprising:
a transceiver;
a memory configured to store instructions; and
at least one processor communicatively coupled with the transceiver and the memory, wherein the at least one processor is configured to:
identifying, for a media access control (MAC) header, a first portion including a first subheader corresponding to a pre-subheader at a beginning location in a MAC packet data unit (PDU) and a second portion including a second subheader corresponding to a post-subheader at an end location in the MAC PDU, the pre-subheader including information to be sent prior to information in the post-subheader, wherein the post-subheader includes information satisfying a data generation time for transmission; and
send, to a network entity on an uplink communication channel, the first portion at a first time and the second portion at a second time after the first time.
9. The apparatus of claim 8 , wherein a size of the pre-subheader is at least one of a fixed size known to one or both of the UE or the network entity, or a variable size indicated at the beginning of the MAC PDU.
10. The apparatus of claim 8 , wherein the MAC PDU includes a cyclic redundancy check (CRC) according to at least one of:
on the pre-subheader,
on the first portion of the MAC PDU covering at least the pre-subheader, or
per MAC control element.
11. The apparatus of claim 8 , wherein the post-subheader includes a header length corresponding to a backward pointer to a beginning of the MAC PDU.
12. The apparatus of claim 8 , wherein the MAC PDU includes a cyclic redundancy check (CRC) according to at least one of:
on the post-subheader,
on the second portion of the MAC PDU covering at least the post-subheader, or
per MAC control element.
13. The apparatus of claim 8 , wherein the at least one processor is further configured to receive an acknowledgment (ACK) including at least one of a control portion or a data portion in response to sending at least the first portion at the first time.
14. The apparatus of claim 8 , wherein the at least one processor is further configured to:
receive, on a downlink communication channel from the network entity, a distinct MAC PDU including a distinct MAC header including at least two portions, the distinct MAC PDU including downlink-specific control elements in at least one of the two portions; and
transmit, on the uplink communication channel to the network entity, an ACK including at least one of a control portion or a data portion in response to receiving the distinct MAC PDU.
15. An apparatus of wireless communications, comprising:
means for identifying, for a media access control (MAC) header, a first portion including a first subheader corresponding to a pre-subheader at a beginning location in a MAC packet data unit (PDU) and a second portion including a second subheader corresponding to a post-subheader at an end location in the MAC PDU, the pre-subheader including information to be sent prior to information in the post-subheader, wherein the post-subheader includes information satisfying a data generation time for transmission; and
means for sending, from the UE to a network entity on an uplink communication channel, the first portion at a first time and the second portion at a second time after the first time.
16. The apparatus of claim 15 , wherein the post-subheader includes a header length corresponding to a backward pointer to a beginning of the MAC PDU.
17. A non-transitory computer-readable medium storing computer executable code for wireless communication, comprising code for:
identifying, for a media access control (MAC) header, a first portion including a first subheader corresponding to a pre-subheader at a beginning location in a MAC packet data unit (PDU) and a second portion including a second subheader corresponding to a post-subheader at an end location in the MAC PDU, the pre-subheader including information to be sent prior to information in the post-subheader, wherein the post-subheader includes information satisfying a data generation time for transmission; and
sending, from the UE to a network entity on an uplink communication channel, the first portion at a first time and the second portion at a second time after the first time.
18. The non-transitory computer-readable medium of claim 17 , wherein the post-subheader includes a header length corresponding to a backward pointer to a beginning of the MAC PDU.