A method for enabling one or more nodes to communicate with an access point (AP) according to a CSMA/CA protocol is provided. In one embodiment of the method, when the individual node enters into a state of having at least one packet of data to be transmitted to the AP, the individual node waits for a non-zero deterministic delay so that any packet arrived during the delay is allowed to be aggregated and transmitted upon one transmission opportunity, thereby improving channel utilization. The delay is determined such that a predicted system throughput is maximized. It is found that the system throughput is significantly affected by the relationship between the delay and the number of the one or more nodes. Hence, the delay is advantageously determined according to the number of the one or more nodes. After the delay expires, the individual node initiates a contending procedure.