Would like to add a router to my home internet to improve Wi-Fi performance in my detached garage apartment. The apartment and my house are part of the same home internet system.
If a router is added, then what issues must be addressed?
Also, is there an additional monthly charge, if I provide my own router?
What type of modem or gateway do you have? If it's a Comcast gatway (modem/router combined), then you don't really need a second router. You can get some form of WiFi extender. If you can run Ethernet cable to a closer point, or even into the room, then a simple Access Point (AP) or an Ethernet switch would do.
The situation is this:
Is this correct?
MoCA adapters may also be an option for you. Google MoCA for more info.
And if you are talking about having two modem / router gateway devices connected to the coax outlets, most systems will not allow two modems to be used at one address. It's best to call in to see what the local policy is. Even if they do allow it you will need to pay for two accounts (twice what you are paying for HSI now). In addition, the signal levels/line quality has to be adequate.