AFAICT, you've got something like this
, possibly using Comcast's Xfinity
moniker. If not, please correct. That said, such a gateway serves 4 functions:
- cable modem
- WiFi access point
- VOIP telephony interface (eMTA)
To improve your home's WiFi coverage, you basically have 3 (sets of) options:
1. Relocating the Gateway to a more central location in your home
. This may obviate the need for a WiFi extender.
2. Adding a compatible range extender to the Comcast Gateway*
. Ideally, you'd like the two WiFi access points (gateway and extender) to be part of the same network, so that you can move your portable devices throughout the house and automatically switch to the best access point depending on location. It may be easier to set up two separate WiFi networks given possible hardware limitations with available extenders, but then you'd have to manually switch when needed.
3. Putting the modem in bridge mode
, effectively disabling routing and wireless, leaving only the modem and VOIP functions (although keeping the latter in bridge mode is firmware dependent). You'd then need another WiFi router and WiFi extender (assuming you'd need the latter; see #1). If you like Apple equipment this could be an Airport Extreme or a Time Capsule (for router/WiFi) and one or more Airport Express units to extend the WiFi network.*
) At this point I cannot make a specific suggestion. That requires some research, or (ideally) someone with the necessary experience to chime in.