the only system I now of that only cares about 10 MHz offset phase noise only would be an optical system, like a sonnet clock. that is because they are mostly concerned with leading edge time jitter, and when you integrate up phase noise from 1 Hz to 1 MHz, it really is not that relevant compared to phase nose integrated from 1 MHz to 20 MHz. there are a lot more Hz of bandwidth in the later.
and even IF you did care a little about closer in phase noise, there is usually a carrier tracking filter somewhere that effectively highpass filters the jitter caused by it...eliminating it.