Quote (Arkhen @ Sep 21 2017 02:23pm)
Keep in mind 15 Mbps (Megabits, small b ) is roughly the equivalent to 1.5 MB/s (Megabyte, capital B). Technically a small margin more in MB, but you get the point.
If your plan is 15 Mbps and you're able to download 1.5 MB/s you're already almost at maximum bandwidth potential. In other words, it doesn't make sense if you're able to download 15 MB/s on a 15 Mbps connection, so I'm not 100% sure I understand your question.
For conversion tables you can check here:
https://www.gbmb.org/mbps-to-mbsAnyway, if your issue is that you're able to download 1.5 MB while wired on the laptop, but only 0.75 - 1.5 MB while on wifi, that's of course something we can look into.
Just to get it out of the way, what laptop are you using (make and model, example: HP 8570W)? If you're unsure you can find its specs by using a tool such as Speccy -
https://www.piriform.com/speccyTo be fair, OP did put 'mb' in the first post, not 'MB'.
That being said, I'd check for updated wireless drivers. I see those resolve issues with certain router chipsets all the time.
@OP: What wireless adapter and driver version does this laptop have?