1) Disable the router function of your Comcast modem/router and get into bridge mode.
2) Connect your Comcast modem (now in bridged mode), to a good 802.11ac router (connect using Cat6 cable). 802.11ac is the most current wireless networking standard. It has taken something good (802.11n), and made it even better. 802.11ac is a faster and more scalable version of 802.11n. It couples the freedom of wireless with the capabilities of Gigabit Ethernet. Another nice thing about 802.11 routers is that you can use open source firmware (DD-WRT, Tomato, OpenWrt). You’ll receive quicker patches (code updates) from these open sources. Awesome!
3) Position your router in a central area of the house/apt./office if possible.
4) Properly configure your 802.11ac router. Here is an example of the basic set-up.
5) If your receiving device is not 802.11ac capable (most new computers, tablets and phones are 802.11ac compatible), don’t worry too much. According to tests performed by SmallNetBuilder.com , 802.11ac routers connecting to 802.11n devices delivered significant wireless improvement. So, you can stay with your 802.11n device or even better, upgrade the receiving device to 802.11ac (wireless NIC, dongle, etc.).
6) Enjoy gigabit wireless speeds!
Best wishes for wireless success,
Randy The Tech Professor