A wireless communication device (alternatively, device) includes a communication interface and a processor, among other possible circuitries, components, elements, etc. to support communications with other wireless communication device(s) and to generate and process signals for such communications. A device is configured to generate various orthogonal frequency division multiplexing (OFDM) and/or orthogonal frequency division multiple access (OFDMA) packets (e.g., frames, signals, etc.) that are based on any of a group of set of OFDM/A frame structures. Across the various OFDM/A frame structures, the ratio of pilot sub-carriers to data sub-carriers across resource units (RUs) of decreases as the total number of sub-carriers across the RUs increases. In addition, some of the OFDM/A frame structures include different total number of sub-carriers yet same number of pilot sub-carriers. The device is configured to perform adaptation among and between the various OFDM/A frame structures based on any one or more considerations.