Sometimes they put the routers in the basement, not your situation.
Anyhow you are only 15 feet away from the router, but the wifi hardware in your earlier laptop only can work so fast with this new technology.
Being it is close by to your laptop you can hardwire that distance with a 20' ethernet cable and bypass the laptop wifi and go right in direct to your motherboard with the ethernet cable.
Can give you a real time test of the speeds your laptop is capable of with the new service.
Speedtest.net
For the line speed tests.
Like Uncorking Your Headers.