For additional reference, there's a Network Extender setup video available on vzw.com.
Ensure that the wireless device is located within a 15-foot radius of the Network Extender. Once registered, coverage is extended up to 5,000 square feet (approximately a 39.5 foot radius) depending on home construction and Network Extender placement.
A short double tone (beep) may be heard while placing or receiving a call.
The device may display a visual indicator in the status bar.
Call #48 from your phone. Review the confirmation announcement:
You are under Network Extender coverage.
The wireless device is registered on and using a Network Extender.
Welcome to Verizon Wireless. You are not under Network Extender coverage. Please move closer to your Network Extender and retry after waiting for 3 minutes. For troubleshooting, please go to support.verizonwireless.com. Announcement 20, switch xxx-xx.
The wireless device hasn't registered on an available Network Extender.