Transmission coordination within multiple user, multiple access, and/or MIMO wireless communications. Within wireless communication systems, there can be various wireless communication devices therein that are not all compliant with a common capability set, communication protocol, communication standard, recommended practice, etc. For example, some communication systems may have some wireless communication devices characterized as ‘legacy’ wireless communication devices, and other wireless communication devices therein may be newer and compliant with newer capability sets, communication protocols, communication standards, recommended practices, etc. In such instances, coordination of transmissions among the various wireless communication devices may be made, when performing simultaneous transmissions, by ensuring that transmissions of devices on different channels is made when aligned on a common boundary of an OFDM symbol. Alternatively, such simultaneous transmissions may be made when offset by some multiple of OFDM symbol duration. When performing non-simultaneous transmissions, transmissions may be made based on channel availability.