15Mbps refers to how much you can download at once, not really the speed. Yes, when downloading a 1 gigabyte movie, you want more bandwith since it will ultimately finish sooner, but when it comes to trading, its different. Even if you monitor 100 instruments at the same time, I doubt this mean you're having to download 1.8 megabytes per second, which is what 15Mbps refers to. For my trading, with TWS open and watching 4 futures instruments in real time plus other symbols that are updating in real time, I see that my usage is about 10-20kbps (kilo bytes per second).
Now if I also browse the intent, this jumps to maybe 100-500kbps, but still well below the 1.8 megabytes per second that your 15Mbps connection would theoretically top out at.
So your connection will have no problem what so ever for trading.
The latency of course is another factor. I'm not sure what the 10ms refers to. This is usually a number of how quickly a signal gets from your house to somewhere else. You might want to ping the server of your broker, to see how quickly a signal gets there. The broker of course has to also send this to the exchange. I'm not an expert in this field, but if you consider that your brain might need about 200ms or more to even interpret something you see, and then even more time to click a button, this will be the rate limiting stop. If you're in the US, the duration of the transmission really won't be a factor.
But honestly, you can't win the speed game at home. If trading limit orders, you'll always be at the back of the que, and if trading market orders, its possible that the bid/ask has moved from when you click to what it is when its filled. This isn't because of a slow connection, but because your brain is like a turtle trying to compete with a cheetah.