Method and apparatus of transmitting paging frame and wakeup frame

A device configured for associating with an access point in a wireless local area network, the device comprising:

• a transceiver that receives and transmits radio signals;
• and
• a processor, operatively coupled with the transceiver, that:
• instructs the transceiver to transmit a request frame to an access point (AP), the request frame including a physical layer header without a data field,
• determines whether a response frame in response to the request frame is received from the AP before a waiting time expires, and
• instructs the transceiver to transmit an association request frame to request an association with the AP if the response frame is received,
• wherein the physical layer header includes a short training field, a long training field and a signal field, the signal field including an indication bit and a cyclic redundancy check (CRC) for the signal field, and
• wherein the indication bit indicates that the request frame has no data field.