Device and Method of Handling a Channel Access Procedure

Abstract

A first base station (BS) for handling a channel access procedure comprising determining a first energy detection threshold, when an energy level or an interference level is lower than or equal to a first threshold; the first BS 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 first 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.

What is claimed is: 
     
         1 . A first 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 first BS determining a first energy detection threshold, when an energy level or an interference level is lower than or equal to a first threshold;   the first BS 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;   the first BS 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   the first BS broadcasting a second SI via the cell of the first 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.   
     
     
         2 . The first BS of  claim 1 , wherein the instructions further comprising:
 transmitting a dedicated radio resource control (RRC) message to the communication device on a RRC connection with the communication device, wherein the dedicated RRC message configures a third energy detection threshold.   
     
     
         3 . The first BS of  claim 2 , wherein the dedicated RRC message configures the third energy detection threshold for the communication device to perform a third channel access procedure according to the third energy detection threshold. 
     
     
         4 . The first BS of  claim 2 , wherein the dedicated RRC message indicates an absolute maximum energy detection threshold value or an offset to a default maximum energy detection threshold value, for configures the third energy detection threshold. 
     
     
         5 . 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.   
     
     
         6 . The second BS of  claim 5 , wherein the handover command indicates an absolute maximum energy detection threshold value or an offset to a default maximum energy detection threshold value, for configures the second energy detection threshold. 
     
     
         7 . 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.   
     
     
         8 . The method of  claim 7 , wherein the instructions further comprising:
 transmitting a dedicated radio resource control (RRC) message to the communication device on a RRC connection with the communication device, wherein the dedicated RRC message configures a third energy detection threshold.   
     
     
         9 . The method of  claim 8 , wherein the dedicated RRC message configures the third energy detection threshold for the communication device to perform a third channel access procedure according to the third energy detection threshold. 
     
     
         10 . The method of  claim 8 , wherein the dedicated RRC message indicates an absolute maximum energy detection threshold value or an offset to a default maximum energy detection threshold value, for configures the third energy detection threshold.