As per manufacturer:

Wireless Home Phone (“WHP”) is a mobile device designed to provide service consistent with other AT&T wireless devices. 9 1 1 calls are routed based on the wireless network’s automatic location technology. For emergency calls, you may have to provide your location address to the 9 1 1 operator. WHP device has a backup battery in the event of a power outage. However, a landline phone requiring separate electric power to operate (e.g., cordless phones) connected to a WHP device will not place or receive calls (including 91 1 calls) during a power outage. Corded/cordless landline home phone equipment is not included. WHP device provides voice service only. Not compatible with data or messaging services, and other services including but not limited to home security systems, fax service, medical alert systems, medical monitoring systems, credit card machines, IP/PBX Phone systems, or dial-up Internet service. May not be compatible with your DVR/Satellite systems, plea

Product Information