Padding and backoff operations when transmitting via multiple frequency segments in a WLAN

A first communication device, comprising:

• a wireless network interface device that is configured to communicate via multiple frequency segments, the wireless network interface device having one or more integrated circuit (IC) devices configured to:
• determine that simultaneous transmission and reception via multiple frequency segments is not permitted,
• control the wireless network interface device to transmit a first packet in a first frequency segment,
• control the wireless network interface device to transmit a second packet in a second frequency segment,
• determine that an end of the first packet does not align with an end of the second packet,
• determine that at least one of the first packet and the second packet prompts transmission of a respective response packet a defined time period after transmission of the corresponding one of the first packet and the second packet, and
• in response to having determined that i) simultaneous transmission and reception via multiple frequency segments is not permitted and ii) at least one of the first packet and the second packet prompts transmission of the respective response packet the defined time period after transmission of the corresponding one of the first packet and the second packet, include, in at least one of the first packet and second packet, padding so that an end of transmission of the first packet is aligned with an end of transmission of the second packet.