Early data transmission in wireless communication system
Provided herein is design of early data transmission in wireless communication system. An apparatus for a user equipment (UE) includes a processor configured to: encode a physical random access channel (PRACH) sequence from a plurality of PRACH sequence for transmission via a PRACH to perform a random access procedure, wherein indication of support of early data transmission (EDT) that is transmitted during the random access procedure is based on at least one of the plurality of PRACH sequences, higher layer signaling, PRACH resources, PRACH formats, and a payload from the UE; and send the PRACH sequence to a radio frequency (RF) interface; and the RF interface to receive the PRACH sequence from the processor. Design of random access response (RAR) is also disclosed herein.
1. An apparatus for a user equipment (UE), comprising:
a processor configured to:
encode a physical random access channel (PRACH) sequence for transmission via a PRACH to perform a random access procedure, wherein indication of support of early data transmission (EDT) that is transmitted during the random access procedure is based on at least one of higher layer signaling, PRACH resources, PRACH sequences, PRACH formats, or a payload from the UE; and
send the PRACH sequence to a radio frequency (RF) interface; and
the RF interface to receive the PRACH sequence from the processor,
wherein the PRACH sequences are divided into different partitions, and one or more partitions of the PRACH sequences are configured to support the EDT.
2. The apparatus of claim 1 , wherein the EDT comprises uplink (UL) transmission and downlink (DL) transmission.
3. The apparatus of claim 1 , wherein the higher layer signaling comprises at least one of a system information (SI) message and dedicated higher layer signaling.
4. The apparatus of claim 1 , wherein the EDT is enabled based on coverage enhancement (CE) levels.
5. The apparatus of claim 1 , wherein the PRACH resources are divided into different partitions, and one or more partitions of the PRACH resources are configured to support the EDT.
6. The apparatus of claim 5 , wherein the PRACH resources comprise one or both of time resources and frequency resources.
7. The apparatus of claim 6 , wherein different frequency hopping patterns are configured for different partitions of the PRACH resources.
8. The apparatus of claim 1 , wherein the partitions of the PRACH sequences are divided based on one or both of root indexes and cyclic shifts.
9. The apparatus of claim 1 , wherein the number of the partitions of the PRACH resources or PRACH sequences is configured to indicate support and/or requirement of multiple transport block size (TBS) values for the EDT.
10. The apparatus of claim 1 , wherein the partitions of the PRACH resources or PRACH sequences are further divided for different coverage enhancement (CE) levels.
11. The apparatus of claim 1 , wherein the partitions of the PRACH resources or PRACH sequences are further divided for uplink (UL) transmission and downlink (DL) transmission of the EDT separately or for both of the UL transmission and the DL transmission of the EDT.
12. The apparatus of claim 1 , wherein the PRACH formats comprises single-tone PRACH and multi-tone PRACH.
13. The apparatus of claim 1 , wherein the payload from the UE is transmitted following the PRACH sequence to indicate whether the UE supports the EDT or not.
14. The apparatus of claim 1 , wherein the payload is further configured to indicate a desired TBS value for UL transmission of the EDT.
15. An apparatus for a user equipment (UE), comprising:
a radio frequency (RF) interface to receive a random access response (RAR) from an access node; and
a processor configured to:
receive the RAR from the RF interface; decode the RAR to obtain an uplink (UL) grant; and
determine whether the UL grant is used for scheduling of early data transmission (EDT) that is transmitted during a random access procedure,
wherein whether the UL grant is used for scheduling of EDT is determined based on an indicator, wherein the indicator is carried via one of an additional bit in the UL grant, a reserved bit in the RAR, an additional bit in the RAR other than the UL grant, a new field in a medium access control (MAC) header for the RAR, or a reserved state indicated by a field of the UL grant.
16. The apparatus of claim 15 , wherein the UL grant comprises a modulation and coding scheme (MCS)/transport block size (TBS) indication field, wherein the MCS/TBS indication field comprises less bits than that for a random access procedure without EDT.
17. The apparatus of claim 15 , wherein the UL grant comprises a MCS/TBS indication field, wherein the MCS/TBS indication field comprises more bits than that for a random access procedure without EDT.
18. The apparatus of claim 15 , wherein the UL grant comprises a modulation and coding scheme (MCS)/transport block size (TBS) indication field, wherein the MCS/TBS indication field is configured to indicate a combination of a modulation scheme and a TBS value.
19. The apparatus of claim 15 , wherein the UL grant comprises a physical resource block (PRB) assignment field, wherein the PRB assignment field comprises less bits than that for a random access procedure without EDT.
20. The apparatus of claim 15 , wherein the UL grant comprises at least one of a UL subcarrier spacing field, a Msg3 subcarrier allocation field, a resource assignment field and a modulation and coding scheme (MCS)/transport block size (TBS) indication field, and wherein at least one of the UL subcarrier spacing field, the Msg3 subcarrier allocation field, the resource assignment field and the MCS/TBS indication field comprises less bits than that for a random access procedure without EDT.
21. The apparatus of claim 15 , wherein one of the additional bit in the UL grant, the reserved bit in the RAR, and the additional bit in the RAR other than the UL grant is configured to indicate whether a field in the UL grant is required to be interpreted in a different way from that for a random access procedure without EDT.
22. The apparatus of claim 15 , wherein the UL grant comprises a second additional bit to indicate offset to a transport block size (TBS) value.
23. The apparatus of claim 15 , wherein the processor is configured to determine the UL grant is used for scheduling of EDT, when the UE transmits a physical random access channel (PRACH) sequence via a PRACH resource that is dedicated for the EDT or the UE transmits a PRACH sequence dedicated for the EDT.
24. An apparatus for a user equipment (UE), comprising:
a processor configured to:
encode a physical random access channel (PRACH) sequence for transmission via a PRACH to perform a random access procedure, wherein indication of support of early data transmission (EDT) is transmitted during PRACH sequences, wherein the PRACH sequences are divided into different partitions, and one or more partitions of the PRACH sequences are configured to support the EDT; and
send the PRACH sequence to a radio frequency (RF) interface; and
the RF interface configured to receive the PRACH sequence from the processor.
25. The apparatus of claim 24 , wherein the partitions of the PRACH sequences are further divided for uplink (UL) transmission and downlink (DL) transmission of the EDT separately, or for both of the UL transmission and the DL transmission of the EDT.