FIELD OF THE DISCLOSURE

The present disclosure relates generally to communication networks and, more particularly, to wireless local area networks that utilize orthogonal frequency division multiplexing (OFDM).

BACKGROUND

The Institute for Electrical and Electronics Engineers (IEEE) 802.11 family of Standards (generally “802.11”) has gone through several iterations over the last decade. In some of the 802.11 standards, such as 802.11ah and beyond, the identity of the Basic Service Set (BSS) (e.g., as managed by an access point (AP) of the BSS) is indicated in a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) by a set of bits that described the “color” of the BSS. The color of a BSS corresponds to an identifier (ID) of the BSS that is shorter than a BSS identifier (BSSID) defined by 802.11. The BSS color may be contained in the Physical Layer (PHY) Signal (SIG) field in a PHY header of a PPDU, whereas the BSSID is typically included in a media access control (MAC) portion of PPDUs. A device (e.g., an AP or client) in a BSS can determine whether a PPDU is from the BSS to which the device belongs (the “same-BSS”) or some other BSS (e.g., an overlapping BSS (OBSS)) by decoding the SIG field and interpreting BSS color bits included therein.

SUMMARY

In an embodiment, a method for generating a physical layer (PHY) data unit for transmission in a shared communication medium during a transmit opportunity (TXOP) includes: generating, at a wireless communication device, a TXOP field to be included in the PHY data unit, the TXOP field generated to indicate a length of time remaining in the TXOP; generating, at the wireless communication device, a PHY preamble of the PHY data unit, the PHY preamble generated to include i) a legacy signal field in a legacy portion of the PHY preamble and ii) a non-legacy signal field in a non-legacy portion of the PHY preamble, wherein generating the PHY preamble includes generating the non-legacy signal field to include the TXOP field; generating, at the wireless communication device, the PHY data unit to include the PHY preamble and a data portion; and transmitting, by the wireless communication device, the PHY data unit in the shared communication medium.

In another embodiment, a wireless network interface device implemented on one or more integrated circuits (ICs), wherein the wireless network interface device is configured to: generate a transmit opportunity (TXOP) field to be included in a PHY data unit for transmission in a shared communication medium during a TXOP of the wireless communication device, the TXOP field generated to indicate a length of time remaining in the TXOP; generate a PHY preamble of the PHY data unit, the PHY preamble generated to include i) a legacy signal field in a legacy portion of the PHY preamble and ii) a non-legacy signal field in a non-legacy portion of the PHY preamble, the wireless network interface device being configured to generate the non-legacy signal field to include the TXOP field; generate the PHY data unit to include the PHY preamble and a data portion; and transmit the PHY data unit in the shared communication medium.

In yet another embodiment, a method for operating in a shared communication medium during a transmit opportunity (TXOP) includes: receiving, at a wireless communication device, a physical layer (PHY) data unit, including receiving a PHY preamble of the PHY data unit, wherein the PHY preamble includes i) a legacy signal field in a legacy portion of the PHY preamble and ii) a non-legacy signal field in a non-legacy portion of the PHY preamble, the non-legacy signal field including a TXOP field; processing, at the wireless communication device, the TXOP field to determine a length of time remaining in the TXOP; setting, at the wireless communication device, a channel access counter based on the length of time remaining in the TXOP determined based on the TXOP field in the non-legacy signal field in the non-legacy portion of the PHY preamble of the PHY data unit; and performing, at the wireless communication device, a channel access procedure using the channel access counter set based on the length of time remaining in the TXOP to defer transmission, by the wireless communication device, in the shared communication medium for at least the length of time remaining in the TXOP.

In still another embodiment, a wireless communication device comprises a wireless network interface device implemented on one or more integrated circuits (ICs), wherein the wireless network interface device is configured to: receive a physical layer (PHY) data unit, including receiving a PHY preamble of the PHY data unit, wherein the PHY preamble includes i) a legacy signal field in a legacy portion of the PHY preamble and ii) a non-legacy signal field in a non-legacy portion of the PHY preamble, the non-legacy signal field including a TXOP field; process the TXOP field to determine a length of time remaining in the TXOP; set a channel access counter based on the determined length of time remaining in the TXOP determined based on the TXOP field in the non-legacy signal field in the non-legacy portion of the PHY preamble of the PHY data unit; and perform a channel access procedure using the channel access counter set based on the length of time remaining in the TXOP to defer transmission, by the wireless communication device, in the shared communication medium for at least the length of time remaining in the TXOP.

