The old Actiontec Rev I units can be setup as a WiFi Access Point. But, they are single band 802.11n only, so max speed is about 130Mbps, with real speeds being lower. Not a bad speed if you use it to give WiFi coverage where non existed before, but certainly not the 300-400Mbps you can get out of a G1100.
To run it in AP mode, you need to put it in bridged network mode, disable DHCP and connect one of it's LAN ports to a LAN port on the G1100. It will pull an IP address from the G1100 once this is done, so be sure to make a note of it so you can login to it in the future. If things get messed up, a factory reset will get it back to a usable state.