There is provided a method for time synchronization of stations (STAs) in a wireless local area network. An access point (AP) transmits a request to at least two STAs for the at least two STAs to transmit a response to the AP, the request indicating which frequency sub-band each of the at least two STAs is to use for transmitting the response. Responses to the request are received from the at least two STAs, wherein each of the responses comprises orthogonal frequency-division multiple access (OFDMA) symbols. For each of the at least two STAs, a time delay is determined based on the responses. Then, control signalling is transmitted to the at least two STAs, the control signalling comprising time alignment commands for the at least two STAs, wherein each time alignment command is based on the time delay for one of the at least two STAs.