A method in a wireless communication network comprising a first Radio Network Node, RNN, and a second Radio Network Node, RNN 120, for assisting a wireless device to perform an uplink transmission to the second RNN, wherein the first RNN, the second RNN and the wireless device are operated in the wireless communications network, wherein the first RNN is configured to serve the wireless device when located in a first cell and the second RNN is configured to serve the wireless device when located in a second cell, wherein the second cell has a size that is below a threshold and arranged to at least partly overlap the first cell, and wherein the method comprises: - triggering (201,301), by a specifc RNN, the specific RNN being the first RNN or the second RNN, the wireless device to perform the uplink transmission using a configured Timing Advance, TA, value and a guard time without performing a preceding random access procedure in the second cell towards the second RNN, wherein the triggering (201,301) further comprises: - transmitting, to the wireless device, by the specific RNN, information relating to one or more resources allocated, for the uplink transmission, to the second RNN; - transmitting, to the wireless device, by the specific RNN, configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; - receiving (202,701), by the wireless device, a trigger configured to trigger the wireless device to perform the uplink transmission using a configured Timing Advance, TA, value and a guard time, wherein the receiving (202,701) further comprises receiving configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; and - performing (206,703), by the wireless device, by means of the configured TA value and the guard time, the uplink transmission to the second RNN without performing a preceding random access procedure in the second cell towards the second RNN. - triggering (201,301), by a specifc RNN, the specific RNN being the first RNN or the second RNN, the wireless device to perform the uplink transmission using a configured Timing Advance, TA, value and a guard time without performing a preceding random access procedure in the second cell towards the second RNN, wherein the triggering (201,301) further comprises: - transmitting, to the wireless device, by the specific RNN, information relating to one or more resources allocated, for the uplink transmission, to the second RNN; - transmitting, to the wireless device, by the specific RNN, configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; - receiving (202,701), by the wireless device, a trigger configured to trigger the wireless device to perform the uplink transmission using a configured Timing Advance, TA, value and a guard time, wherein the receiving (202,701) further comprises receiving configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; and - performing (206,703), by the wireless device, by means of the configured TA value and the guard time, the uplink transmission to the second RNN without performing a preceding random access procedure in the second cell towards the second RNN. - transmitting, to the wireless device, by the specific RNN, information relating to one or more resources allocated, for the uplink transmission, to the second RNN; - transmitting, to the wireless device, by the specific RNN, configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; - receiving (202,701), by the wireless device, a trigger configured to trigger the wireless device to perform the uplink transmission using a configured Timing Advance, TA, value and a guard time, wherein the receiving (202,701) further comprises receiving configuration information that is configured to instruct the wireless device to use the configured TA value and the guard time when performing the uplink transmission; and - performing (206,703), by the wireless device, by means of the configured TA value and the guard time, the uplink transmission to the second RNN without performing a preceding random access procedure in the second cell towards the second RNN.