Method and apparatus for indicating a frame type using a preamble
Disclosed are a method and a device for transmitting a data block. The method involves generating and transmitting a physical layer protocol data unit (PPDU) that includes a short training field, a long training field and a signal field. The signal field includes a frame type field that has a length of one bit and indicates whether the PPDU includes a control medium access control (MAC) frame. The device is capable of performing the method.
1. A method for transmitting a data block in a wireless local area network, the method comprising:
generating, by a transmitter, a physical layer protocol data unit (PPDU) that includes a short training field, a long training field and a signal field; and
transmitting, by the transmitter, the PPDU to a receiver,
wherein the signal field includes a frame type field that indicates whether the PPDU is used to carry a null data packet (NDP) frame that does not have a data field,
wherein when the frame type field does not indicate that the PPDU is used to carry the NDP frame, the signal field includes a bandwidth field, a stream field, a modulation and coding scheme (MCS) field, and a coding type field, the bandwidth field indicating a bandwidth used for the PPDU, the stream field indicating a number of spatial streams used for the PPDU, the MCS field indicating a MCS index used for the PPDU, the coding type field indicating a type of channel coding used for the PPDU, and
wherein when the frame type field indicates that the PPDU is used to carry the NDP frame, the signal field indicates a type of the NDP frame and does not include the MCS field.
2. The method of claim 1 , wherein the PPDU is transmitted over 1 MHz bandwidth.
3. The method of claim 1 , wherein each of the short training field, the long training field and the signal field is transmitted in two Orthogonal Frequency Division Multiplexing (OFDM) symbols.
4. The method of claim 1 , wherein the receiver determines whether to stop receiving the PPDU based on the frame type field.
5. A device for transmitting a data block in a wireless local area network, the device comprising:
a transceiver that transmits and receives radio signals; and
a processor, operatively coupled with the transceiver, that:
generates a physical layer protocol data unit (PPDU) that includes a short training field, a long training field and a signal field; and
instructs the transceiver to transmit the PPDU to a receiver,
wherein the signal field includes a frame type field that indicates whether the PPDU is used to carry a null data packet (NDP) frame that does not have a data field,
wherein when the frame type field does not indicate that the PPDU is used to carry the NDP frame, the signal field includes a bandwidth field, a stream field, a modulation and coding scheme (MCS) field, and a coding type field, the bandwidth field indicating a bandwidth used for the PPDU, the stream field indicating a number of spatial streams used for the PPDU, the MCS field indicating a MCS index used for the PPDU, the coding type field indicating a type of channel coding used for the PPDU,
wherein when the frame type field indicates that the PPDU is used to carry the NDP frame, the signal field indicates a type of the NDP frame and does not include the MCS field.
6. The device of claim 5 , wherein the PPDU is transmitted over 1 MHz bandwidth.
7. The device of claim 5 , wherein each of the short training field, the long training field and the signal field is transmitted in two Orthogonal Frequency Division Multiplexing (OFDM) symbols.
8. The device of claim 5 , wherein the receiver determines whether to stop receiving the PPDU based on the frame type field.