Methods and apparatuses for 2-step random access

An apparatus, comprising:

• at least one memory;
• and
• at least one processor coupled with the at least one memory and configured to cause the apparatus to:
• receive configurations from a base station (BS);
• and
• associate, based at least in part on the configurations, at least one first preamble for a first type of user equipments (UEs) with at least one first physical uplink shared channel (PUSCH) resource unit (PRU) configured for the first type of UEs or at least one unused second PRU configured for a second type of UEs according to at least one of a mapping indication, a mapping ratio, an ordering of the at least one first preamble, an ordering of the at least one unused second PRU or an ordering of the at least one first PRU;
• wherein the at least one first preamble is ordered together with at least one second preamble for the second type of UEs and having an index equal to at least one index of the at least one second preamble plus an offset, or the at least one first preamble is ordered separately from the at least one second preamble;
• and
• wherein the at least one first PRU is ordered together with at least one second PRU and having an index greater than at least one index of the at least one second PRU, or the at least one first PRU is ordered separately from the at least one second PRU.

An apparatus, comprising:

• at least one memory;
• and
• at least one processor coupled with the at least one memory and configured to cause the apparatus to:
• send configurations to a user equipment (UE),
• associate, based at least in part on the configurations, at least one first preamble for a first type of user equipments (UEs) with at least one first physical uplink shared channel (PUSCH) resource unit (PRU) configured for the first type of UEs or at least one unused second PRU configured for a second type of UEs according to at least one of a mapping indication, a mapping ratio, an ordering of the at least one first preamble, an ordering of the at least one unused second PRU or an ordering of the at least one first PRU;
• wherein the at least one first preamble is ordered together with at least one second preamble for the second type of UEs and having an index equal to at least one index of the at least one second preamble plus an offset, or the at least one first preamble is ordered separately from the at least one second preamble;
• and
• wherein the at least one first PRU is ordered together with at least one second PRU and having an index greater than at least one index of the at least one second PRU, or the at least one first PRU is ordered separately from the at least one second PRU.

A method for random access, comprising:

• sending configurations to a user equipment (UE),
• associating, based at least in part on the configurations, at least one first preamble for a first type of user equipments (UEs) with at least one first physical uplink shared channel (PUSCH) resource unit (PRU) configured for the first type of UEs or at least one unused second PRU configured for a second type of UEs according to at least one of a mapping indication, a mapping ratio, an ordering of the at least one first preamble, an ordering of the at least one unused second PRU or an ordering of the at least one first PRU;
• wherein the at least one first preamble is ordered together with at least one second preamble for the second type of UEs and having an index equal to at least one index of the at least one second preamble plus an offset, or the at least one first preamble is ordered separately from the at least one second preamble;
• and
• wherein the at least one first PRU is ordered together with at least one second PRU and having an index greater than at least one index of the at least one second PRU, or the at least one first PRU is ordered separately from the at least one second PRU.