Method and apparatus for communication in wireless communication system using unlicensed band
A 5 th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than a 4 th generation (4G) communication system such as long term evolution (LTE) is provided. A method and apparatus which perform communication in a wireless communication system using an unlicensed band, and a method in which a base station controls a clear channel assessment (CCA) timing in a wireless communication system using an unlicensed band are provided. The method includes determining whether to change CCA timing by comparing a number of at least one of continuous successes or continuous failures in a CCA with a predetermined threshold value and when it is determined that the CCA timing is to be changed, randomizing the CCA timing.
1. A method of controlling clear channel assessment (CCA) timing by a base station in a wireless communication system using an unlicensed band, the method comprising: determining whether to change CCA timing by comparing a number of at least one of continuous successes or continuous failures of the CCA with a predetermined threshold value; randomizing the CCA timing when the CCA timing is determined to be changed; and updating a frame based on the CCA timing changed according to the randomization of the CCA timing.
2. The method of claim 1 , wherein the randomizing of the CCA timing is performed at a sub-frame level or at a symbol level.
3. The method of claim 2 , wherein the randomizing of the CCA timing comprises:
selecting a predetermined number corresponding to a sub-frame number when the CCA timing is randomized at the sub-frame level; and
performing the CCA from a sub-frame corresponding to the selected number for a next fixed frame period.
4. The method of claim 2 , wherein the randomizing of the CCA timing comprises:
selecting a predetermined number corresponding to a sub-frame number when the CCA timing is randomized at the symbol level; and
performing the CCA from a symbol corresponding to the selected number for a next fixed frame period.
5. The method of claim 1 , wherein the randomizing of the CCA timing further comprises randomizing an ON/OFF period of the CCA.
6. A base station for controlling clear channel assessment (CCA) timing in a wireless communication system using an unlicensed band, the base station comprising: a transceiver configured to transmit and receive data; and at least one processor configured to: determine whether to change CCA timing by comparing a number of at least one continuous successes or continuous failures of the CCA with a predetermined threshold value, control randomization of the CCA timing when the CCA timing is determined to be changed, and control updating of a frame based on the CCA timing changed according to the randomization of the CCA timing.
7. The base station of claim 6 , wherein the randomization of the CCA timing is performed at a sub-frame level or at a symbol level.
8. The base station of claim 7 , wherein the at least one processor is further configured to:
select a predetermined number corresponding to a sub-frame number when the CCA timing is randomized at the sub-frame level; and
perform the CCA from a sub-frame corresponding to the selected number for a next fixed frame period.
9. The base station of claim 7 , wherein the at least one processor is further configured to:
select a predetermined number corresponding to a sub-frame number when the CCA timing is randomized at the symbol level; and
perform the CCA from a symbol corresponding to the selected number for a next fixed frame period.
10. The base station of claim 6 , wherein the at least one processor is further configured to control randomization of an ON/OFF period of the CCA.