Described herein is a system and method for enhanced channel access in existing communication networks. The system comprising: a first enhanced node comprising a first processor, the first processor configured to: transmit a legacy frame header of a physical layer protocol data unit (PPDU), the legacy frame header comprising an indicator indicating that sub-PPDUs will be transmitted during a duration associated with transmission of a legacy PPDU; a second enhanced node comprising a second processor configured to receive the legacy frame header; and a third enhanced node comprising a third processor configured to receive the legacy frame header.