Patent ID: 7391746

Claim:
A power saving method in a wireless LAN system, comprising the steps of: determining, from Association Response information received from a base station when a terminal station is subordinate to said base station, whether said base station is a base station capable of transmitting an empty data frame in response to a signal even when said base station does not have data destined to said terminal station; upon receipt of a signal at said base station from said terminal station subordinate to said base station for prompting a transmission of data destined to said terminal station, transmitting an ACK signal indicative of a successful reception of the signal to said terminal station, and transmitting a data frame including data destined to said terminal station when there is such data, and transmitting an empty data frame when there is no data destined to said terminal station; and upon receipt of the data frame at said terminal station and only when said terminal station is subordinate to said base station, transmitting an ACK signal to said base station and transitioning to a state in which a transmission/reception function is made inactive.