Supplementary uplink for random access procedures

A wireless device comprising:

• one or more processors;
• and
• memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
• receive at least one configuration parameter for a cell, wherein the cell comprises a downlink carrier, a normal uplink carrier, and a supplementary uplink carrier;
• determine a channel occupancy level of the normal uplink carrier;
• and
• send, based on the channel occupancy level of the normal uplink carrier, a message via the supplementary uplink carrier.

A system comprising:

• a wireless device;
• and
• a base station,
• wherein the base station is configured to:
• transmit, to the wireless device, at least one configuration parameter for a cell, wherein the cell comprises a downlink carrier, a normal uplink carrier, and a supplementary uplink carrier;
• and
• wherein the wireless device is configured to:
• receive at least one configuration parameter for a cell, wherein the cell comprises a downlink carrier, a normal uplink carrier, and a supplementary uplink carrier;
• determine a channel occupancy level of the normal uplink carrier;
• and
• send, based on the channel occupancy level of the normal uplink carrier, a message via the supplementary uplink carrier.