The base station connects over the cellular network. If it is not connecting during the activation process, it could be because there is low cell signal in your location.
Try moving the base station closer to a window in your location where it may have better cellular reception. Try not to co-located the sensor with other wireless hardware when possible.
Confirm there is an adequate cellular signal at the location. Dor uses T-Mobile 3G or Verizon LTE depending on the location.
If the base station will still not connect, take note of the color and pattern of the LED status light and contact us.