I have a cable modem/router at the other end of the house and a Cisco Linksys E3000 right in my room. They both broadcast under the same SSID (
Aperture Laboratories) in the 2.4 GHz frequency.
The cable modem/router thing only has 2.4 GHz support whereas the router in my room supports both 2.4 GHz and 5 GHz. Since 2.4 GHz is better at long distances (and devices fall back from 5 GHz to 2.4 GHz anyway when the wireless signal is weak) and 5 GHz is less crowded, I decided to give 5 GHz network a different SSID (
Aperture Science). I use that one just with my MBA, iPad and my phone when I'm in my room.