Device and Method of Handling a Channel Access Procedure

A second base station (BS) for handling a channel access procedure, comprising:

• a storage device;
• and
• a processing circuit, coupled to the storage device, wherein the storage device stores instructions, and the processing circuit is configured to execute the instructions of:
• the second BS broadcasting system information (SI) via a cell of the second BS on an unlicensed carrier, wherein the SI configures a first energy detection threshold for a plurality of communication devices to perform a first plurality of channel access procedures according to the first energy detection threshold;
• the second BS receiving a handover request message requesting a handover for a communication device, from a first BS;
• and
• the second BS transmitting a handover request acknowledge message comprising a handover command to the first BS, in response to the handover request message, wherein the handover command orders the communication device to hand over to the cell and indicates a second energy detection threshold for the communication device to perform a second channel access procedure on the unlicensed carrier of the cell according to the second energy detection threshold.

A method for handling a channel access procedure of a base station (BS), comprising:

• determining a first energy detection threshold, when an energy level or an interference level is lower than or equal to a first threshold;
• broadcasting first system information (SI) via a cell, wherein the first SI configures the first energy detection threshold for a communication device to perform a first channel access procedure on an unlicensed carrier according to the first energy detection threshold;
• determining a second energy detection threshold, when the energy level or the interference level is higher than the first threshold or a second threshold;
• and
• broadcasting a second SI via the cell of the BS on the unlicensed carrier, wherein the second SI configures the second energy detection threshold for the communication device to perform a second channel access procedure on the unlicensed carrier according to the second energy detection threshold.