Security Cameras are moving toward high definition at an alarming rate and to keep up with the change many customers are replacing their analog cameras with Megapixel IP Security Cameras. Typically these Megapixel IP cameras use Cat5 or Cat6 cable to power and transmit the data back to the POE switch or NVR system in general. However because of the amount of data that is transmitted from these cameras you can't get the high definition resolution out of the coax cable on its own, you have to use an Ethernet over Coax adaptor.
With an Ethernet over Coax or Ethernet and POE over Coax adaptor you can use your existing coax cable to run Megapixel IP Cameras! Depending on the Ethernet over Coax module you purchase you will need to purchase 1 adaptor for the camera end, and one at the NVR/Switch end.