Apparatus and method for reception and transmission of control channels

An apparatus comprising:

• a controller that
• operates a first serving cell on a licensed carrier frequency and a second serving cell on an unlicensed carrier frequency,
• performs a listen before talk (LBT) on the unlicensed carrier frequency for a first time duration, and
• determines that the unlicensed carrier frequency is free;
• and
• a transceiver coupled to the controller, where the transceiver
• transmits an activation command on the first serving cell for receipt by a user equipment (UE), the activation command being configured to activate the UE to receive transmissions from the apparatus on the second serving cell, and
• transmits, after determining that the unlicensed carrier frequency is free, a reserve transmission on the unlicensed carrier frequency at least until the apparatus begins transmission of the activation command on the first serving cell.

A base station for wireless communication, comprising:

• at least one memory;
• and
• at least one processor coupled with the at least one memory and configured to cause the base station to:
• operate a first serving cell on a licensed carrier frequency and a second serving cell on an unlicensed carrier frequency;
• perform a listen before talk (LBT) on the unlicensed carrier frequency for a first time duration;
• determine that the unlicensed carrier frequency is free;
• transmit an activation command on the first serving cell for receipt by a user equipment (UE), the activation command being configured to activate the UE to receive transmissions from the base station on the second serving cell;
• and
• transmit after determining that the unlicensed carrier frequency is free, a reserve transmission on the unlicensed carrier frequency at least until the base station begins transmission of the activation command on the first serving cell.