Downlink OFDMA for service sets with mixed client types

An apparatus comprising:

• at least one transmitter and a receiver respectively configured to transmit wireless signals to and receive wireless signals from first and second devices having lower and higher bandwidth capabilities, and configured to operate at lower and higher data rates, respectively;
• and
• a controller configured to be coupled to the at least one transmitter and the receiver, wherein the controller is configured to:
• contend for bandwidth to determine bandwidth available for downlink transmissions;
• generate control parameters including information that:
• assigns, from the bandwidth available, first and second non-overlapping channel bandwidths for first and second downlink transmissions to the first and second devices, respectively;
• indicates timing for an acknowledgement to be sent from the first device and after which an acknowledgement from the second device is to be sent;
• and
• schedules the first and second downlink transmissions under a constraint that the first downlink transmission is to be longer than the second downlink transmission, such that the first and second downlink transmissions end before receiving the acknowledgements;
• cause the at least one transmitter to transmit, on the first and second non-overlapping channel bandwidths in advance of a downlink transmission interval, a control frame containing the control parameters;
• cause the at least one transmitter to transmit during the downlink transmission interval a first downlink transmission of data to the first device over the first channel bandwidth at the lower data rate during a first time interval;
• and
• cause the at least one transmitter to transmit during the downlink transmission interval a second downlink transmission of data to the second device over the second channel bandwidth at the higher data rate during a second time interval that partially overlaps with and ends at or before the first time interval.

A non-transitory computer readable medium storing instructions that, when executed by a processor, cause the processor to:

• at a wireless access point that serves first and second devices configured to communicate wirelessly with the access point, having lower and higher bandwidth capabilities, and configured to operate at lower and higher data rates, respectively:
• contend for bandwidth to determine bandwidth available for downlink transmissions;
• generate control parameters including information that:
• assigns, from the bandwidth available, first and second non-overlapping channel bandwidths for first and second downlink transmissions to the first and second devices, respectively;
• indicates timing for an acknowledgement to be sent from the first device and after which an acknowledgement from the second device is to be sent;
• and
• schedules the first and second downlink transmissions under a constraint that the first downlink transmission is to be longer than the second downlink transmission, such that the first and second downlink transmissions end before receiving the acknowledgements;
• cause a transmitter to transmit, on the first and second non-overlapping channel bandwidths in advance of a downlink transmission interval, a control frame containing the control parameters;
• cause the transmitter to transmit during the downlink transmission interval a first downlink transmission of data to the first device over the first channel bandwidth at the lower data rate during a first time interval;
• and
• cause the transmitter to transmit during the downlink transmission interval a second downlink transmission of data to the second device over the second channel bandwidth at the higher data rate during a second time interval that partially overlaps with and ends at or before the first time interval.