Methods of prioritized two-step random access channel (RACH) in new radio (NR)

1 . A method implemented by a network node that is configured to communicate with a wireless device, the method comprising:

transmitting a first random access channel, RACH, configuration for prioritized 2-step random access, RA, signaling, the first RACH configuration including at least a power ramping step for power ramping at least one of a preamble part and physical uplink shared channel, PUSCH, part of a message A, msgA, of the prioritized 2-step RA signaling;

transmitting a second RACH configuration for non-prioritized 2-step RA signaling, the second RACH configuration being separately configured from the first RACH configuration, the power ramping step of the first RACH configuration having a larger power step size than a power step size of the second RACH configuration; and

performing the prioritized 2-step RA signaling using the first RACH configuration based on a traffic type associated with data to be transmitted by the wireless device.

2 . The method claim 1 , wherein the first RACH configuration for prioritized 2-step RA signaling includes a scaling factor for a backoff indicator.

3 . The method of claim 2 , wherein the scaling factor of the first RACH configuration corresponds to a shorter time window from which to select a backoff time than a time window for selecting a backoff time in the second RACH configuration for the RA signaling.

4 . The method of claim 1 , wherein the transmission of the first RACH configuration corresponds to broadcasting the first RACH configuration in a system information block (SIB).

5 . The method of claim 1 , wherein the first RACH configuration is configured for contention free based random access; and

the second RACH configuration is configured for contention based random access.

6 . A method implemented by a wireless device that is configured to communicate with a network node, the method comprising:

receiving a first random access channel, RACH, configuration for prioritized 2-step random access, RA, signaling, the first RACH configuration including at least a power ramping step for power ramping a preamble part and physical uplink shared channel, PUSCH, part of a message A, msg A, of the prioritized 2-step RA signaling;

receiving a second RACH configuration for non-prioritized 2-step RA signaling, the second RACH configuration being separately configured from the first RACH configuration, the power ramping step of the first RACH configuration having a larger power step size than a power step size of the second RACH configuration;

determining whether to use the first RACH configuration for prioritized 2-step random access, RA, signaling or the second RACH configuration for non-prioritized 2-step RA signaling for transmitting data based on a traffic type associated with the data; and

performing prioritized 2-step RA signaling using the first RACH configuration based on the determination.

7 . The method of claim 6 , wherein the first RACH configuration for prioritized 2-step RA signaling includes a scaling factor for a backoff indicator.

8 . The method of claim 7 , wherein the scaling factor of the first RACH configuration corresponds to a shorter time window from which to select a backoff time than a time window for selecting a backoff time in the second RACH configuration for the RA signaling.

9 . The method of claim 6 , wherein the first RACH configuration is received in a broadcast of a system information block (SIB).

10 . The method of claim 6 , wherein the first RACH configuration is configured for contention free based random access; and

the second RACH configuration is configured for contention based random access.

11 . A network node configured to communicate with a wireless device, the network node comprising:

processing circuitry configured to:

transmit a first random access channel, RACH, configuration for prioritized 2-step random access, RA, signaling, the first RACH configuration including at least a power ramping step for power ramping at least one of a preamble part and physical uplink shared channel, PUSCH, part of a message A, msgA, of the prioritized 2-step RA signaling;

transmit a second RACH configuration for non-prioritized 2-step RA signaling, the second RACH configuration being separately configured from the first RACH configuration, the power ramping step of the first RACH configuration has a larger power step size than a power step size of the second RACH configuration; and

perform the prioritized 2-step RA signaling using the first RACH configuration based a traffic type associated with data to be transmitted by the wireless device.

12 . The network node according to claim 11 , wherein the first RACH configuration for prioritized 2-step RA signaling includes a scaling factor for a backoff indicator.

13 . A wireless device configured to communicate with a network node, the wireless device comprising:

processing circuitry configured to:

receive a first random access channel, RACH, configuration for prioritized 2-step random access, RA, signaling, the first RACH configuration including at least a power ramping step for power ramping a preamble part and physical uplink shared channel, PUSCH, part of a message A, msgA, of the prioritized 2-step RA signaling;

receive a second RACH configuration for non-prioritized 2-step RA signaling, the second RACH configuration being separately configured from the first RACH configuration, the power ramping step of the first RACH configuration having a larger power step size than a power step size of the second RACH configuration;

determine whether to use the first RACH configuration for prioritized 2-step random access, RA, signaling or the second RACH configuration for non-prioritized 2-step RA signaling for transmitting data based on a traffic type associated with the data; and

perform prioritized 2-step RA signaling using the first RACH configuration based on the determination.

14 . The wireless device according to claim 13 , wherein the first RACH configuration for prioritized 2-step RA signaling includes a scaling factor for a backoff indicator.