Applications greater than 250Mbps

You need to define "low power" in terms of watts, current, voltage, etc. that means different things to different people . I hope this isn't a homework question because it sounds like one. I found this wiki article within about 10 seconds of googling http://en.wikipedia.org/wiki/List_of_device_bit_rates

Netflix 4k?

Are you aiming for any specific industry...?

@planarmetamaterials I'm designing a UWB transmitter that should be able to work at that data rates with low powers.