Methods and apparatus for generation of physical layer protocol data units

1. A method, performed at a first communication device, for transmitting a physical layer (PHY) protocol data unit (PPDU), the method comprising:

receiving an initiating PPDU from a second communication device, the initiating PPDU having a PHY header that indicates a first PPDU format of the initiating PPDU, wherein the initiating PPDU includes one or more fields that indicate one or both of i) whether the second communication device is capable of processing PPDUs that conform to a non-legacy communication protocol, and ii) whether the second communication device neighbors any third communication devices that are not capable of processing PPDUs that conform to the non-legacy communication protocol, and wherein the one or more fields of the initiating PPDU indicate a second PPDU format of a responding PPDU to be transmitted in response to the initiating PPDU;

generating the responding PPDU using the second PPDU format; and

transmitting the responding PPDU in response to the initiating PPDU.

2. The method of claim 1 , wherein the first PPDU format is a non-legacy PPDU format and the second PPDU format is a legacy PPDU format.

3. The method of claim 1 , wherein:

the PHY header of the initiating PPDU has a modulation and coding scheme (MCS) field that indicates a modulation and coding scheme of the initiating PPDU; and

generating the responding PPDU comprises generating the responding PPDU using the second PPDU format and the modulation and coding scheme indicated by the MCS field.

4. The method of claim 1 , wherein:

the initiating PPDU includes a medium access control (MAC) protocol data unit (MPDU) delimiter having an MPDU length field that indicates an octet length of a corresponding MPDU of the initiating PPDU.

5. The method of claim 1 , wherein:

the initiating PPDU includes a PHY header having an MPDU length field that indicates an octet length of a corresponding MPDU of the initiating PPDU.

6. A first communication device, comprising:

a network interface device configured to:

receive an initiating physical layer (PHY) protocol data unit (PPDU) from a second communication device, the initiating PPDU having a PHY header that indicates a first PPDU format of the initiating PPDU, wherein the initiating PPDU includes one or more fields that indicate one or both of i) whether the second communication device is capable of processing PPDUs that conform to a non-legacy communication protocol, and ii) whether the second communication device neighbors any third communication devices that are not capable of processing PPDUs that conform to the non-legacy communication protocol, and wherein the one or more fields of the initiating PPDU indicate a second PPDU format of a responding PPDU to be transmitted in response to the initiating PPDU,

generate the responding PPDU using the second PPDU format, and

transmit the responding PPDU in response to the initiating PPDU.

7. The first communication device of claim 6 , wherein the first PPDU format is a non-legacy PPDU format and the second PPDU format is a legacy PPDU format.

8. The first communication device of claim 6 , wherein:

the PHY header of the initiating PPDU has a modulation and coding scheme (MCS) field that indicates a modulation and coding scheme of the initiating PPDU; and

the network interface device is configured to generate the responding PPDU using the second PPDU format and the modulation and coding scheme indicated by the MCS field.

9. The first communication device of claim 6 , wherein:

the initiating PPDU includes a medium access control (MAC) protocol data unit (MPDU) delimiter having an MPDU length field that indicates an octet length of a corresponding MPDU of the initiating PPDU.

10. The first communication device of claim 6 , wherein:

the initiating PPDU includes a PHY header having an MPDU length field that indicates an octet length of a corresponding MPDU of the initiating PPDU.