A method for wireless communication, the method comprising: receiving, by the user equipment, a downlink assignment for a media access control, MAC, random access response, RAR, protocol data unit, PDU, wherein the downlink assignment is scrambled with a random access-radio network temporary identifier, RA-RNTI, that is calculated at least in part based on an index of a single uplink, and wherein the single uplink is one of a plurality of uplinks configured for a single downlink on a same cell, the plurality of uplinks including an uplink, UL, and a supplementary uplink, SUL, and the SUL being on a lower frequency band than the UL; and receiving, by a user equipment from a base station, the MAC RAR PDU, wherein the MAC RAR PDU includes one or more RARs, each of the one or more RARs being associated with the single uplink, wherein the MAC RAR PDU is associated with the RA-RNTI, and wherein the MAC RAR PDU further includes a backoff indicator associated with the single uplink; determining, by the user equipment, that the MAC RAR PDU is associated with the RA-RNTI based on the downlink assignment; determining, by the user equipment, the backoff indicator is associated with the single uplink based on the RA-RNTI associated with the MAC RAR PDU; backing off, by the user equipment, from performing a random access procedure for accessing the single uplink for a time period based on the backoff indicator; and performing, by the user equipment, the random access procedure for accessing the single uplink after the time period. receiving, by the user equipment, a downlink assignment for a media access control, MAC, random access response, RAR, protocol data unit, PDU, wherein the downlink assignment is scrambled with a random access-radio network temporary identifier, RA-RNTI, that is calculated at least in part based on an index of a single uplink, and wherein the single uplink is one of a plurality of uplinks configured for a single downlink on a same cell, the plurality of uplinks including an uplink, UL, and a supplementary uplink, SUL, and the SUL being on a lower frequency band than the UL; and wherein the downlink assignment is scrambled with a random access-radio network temporary identifier, RA-RNTI, that is calculated at least in part based on an index of a single uplink, and wherein the single uplink is one of a plurality of uplinks configured for a single downlink on a same cell, the plurality of uplinks including an uplink, UL, and a supplementary uplink, SUL, and the SUL being on a lower frequency band than the UL; and receiving, by a user equipment from a base station, the MAC RAR PDU, wherein the MAC RAR PDU includes one or more RARs, each of the one or more RARs being associated with the single uplink, wherein the MAC RAR PDU is associated with the RA-RNTI, and wherein the MAC RAR PDU further includes a backoff indicator associated with the single uplink; wherein the MAC RAR PDU includes one or more RARs, each of the one or more RARs being associated with the single uplink, wherein the MAC RAR PDU is associated with the RA-RNTI, and wherein the MAC RAR PDU further includes a backoff indicator associated with the single uplink; determining, by the user equipment, that the MAC RAR PDU is associated with the RA-RNTI based on the downlink assignment; determining, by the user equipment, the backoff indicator is associated with the single uplink based on the RA-RNTI associated with the MAC RAR PDU; backing off, by the user equipment, from performing a random access procedure for accessing the single uplink for a time period based on the backoff indicator; and performing, by the user equipment, the random access procedure for accessing the single uplink after the time period.