Boss302 makes a good point. I'll add that incoming signal strength can be monitored at any time, by interrogating the cable modem. You may wish to do that in the future if performance problems arise.
That can be done from any computer in the house that is networked to the modem, by entering a certain 192.xxx.xxx.x (local) address into a web browser program.
The address to enter depends on the particular modem model, and can usually be readily determined by Googling the make and model number. A password may have to be entered as well, which will also be indicated in some of those search results if it is needed.
Regards,
-- Al