Operating in power save mode
A method for operating in a power save mode for a wireless local area network and a device using the same are provided. After waking up, a device receives a frame via a wireless medium to determine that the wireless medium is busy. If a decoding of the frame in a medium access control (MAC) layer is unsuccessful but a decoding of the frame in a physical layer is successful, the device determines an Interframe space (IFS) to defer an access of the wireless medium.
1. A method for a wireless local area network performed by an access point (AP), the method comprising:
generating a physical layer protocol data unit (PPDU) comprising a first part and a second part, the first part comprising a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG) and a signal-A field, the second part comprising a STF field, a LTF field and a data portion; and
transmitting the PPDU;
wherein the first part having a first Fourier transform (FFT) size and the second part having a second FFT size, wherein the second FFT size is four times the first FFT size,
wherein the data portion comprising an aggregated-medium access control (MAC) protocol data unit (A-MPDU), the A-MPDU comprising a data frame and a control frame,
wherein the data frame comprising a duration field and a MAC address expressed with a first number of bits;
wherein the control fame comprising an association identifier (AID) identifying a receiving station and expressed with a second number of bits;
wherein the second number of bits is less than the first number of bits; and
wherein, when the AP has no data to be sent to the receiving station, the data frame is a Quality of Service (QoS) Null frame, and the MAC address of the QoS Null frame identifies the receiving station; the duration field indicates duration of the control frame.
2. The method of claim 1 , wherein the AID has 2 octets and the MAC address has 6 octets.
3. The method of claim 1 , wherein a MAC header size of the control frame is less than a MAC header size of the data frame.
4. A device for a wireless local area network, the device comprising:
a processor; and
a memory coupled with the processor and storing instructions that when executed by the processor cause the device to:
generate a physical layer protocol data unit (PPDU) comprising a first part and a second part, the first part comprising a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG) and a signal-A field, the second part comprising a STF field, a LTF field and a data portion; and
transmit the PPDU;
wherein the first part having a first Fourier transform (FFT) size and the second part having a second FFT size, wherein the second FFT size is four times the first FFT size,
wherein the data portion comprising an aggregated-medium access control (MAC) protocol data unit (A-MPDU), the A-MPDU comprising a data frame and a control frame,
wherein the data frame comprising a duration field and a MAC address expressed with a first number of bits;
wherein the control fame comprising an association identifier (AID) identifying a receiving station and expressed with a second number of bits;
wherein the second number of bits is less than the first number of bits; and
wherein, when the device has no data to be sent to the receiving station, the data frame is a Quality of Service (QoS) Null frame, and the MAC address of the QoS Null frame identifies the receiving station; the duration field indicates duration of the control frame.
5. The device of claim 4 , wherein the AID has 2 octets and the MAC address has 6 octets.
6. The device of claim 4 , wherein a MAC header size of the control frame is less than a MAC header size of the data frame.