What is a CAM (conditional access module)?

It’s the access card in your receiver. Actually it’s the access card and the thing it connects to, they sort of work as a team.

Conditional Access is a term that was popular about 20 years ago when the world was first getting a look at today’s satellite television. Before DIRECTV and DISH, all satellite TV was unencrypted, or required special hardware decryption on a channel by channel basis.

See, satellite television was always thought of as a way to get content from place to place. It was thought that it would be used for transfers from a remote location to a network broadcast center, and so there was no need for security. Even more importantly, satellite equipment was very expensive and it was never expected that an average person would be able to afford it. Yet, by the 1980s it was possible to get a satellite dish for the equivalent of a few month’s rent of a decent apartment so people started doing it so they could get all the premium channels for free.

Obviously that wasn’t going to stand for long.

The entire idea of satellite television as we know it was based on the idea that content providers could get paid for what they put over the air, and with the blessing of Congress and the FCC, companies like DIRECTV and DISH started developing technologies for making that possible. In general, this technology was called “conditional access.”

A conditional access module has two parts. There is a smart card which contains information that is unique to the receiver and the account, and a module which stores programming information for the account after it is downloaded from the satellite. The third part of the system is a satellite transponder that is literally sending long streams of account numbers, access cards, and programming information 24 hours a day. That information is accessed by the satellite receiver and stored, so the receiver knows which channels can be showed to the customer.

People don’t use the term “CAM” much anymore unless you’re having a real problem with your receiver. If your access card goes bad you can have it replaced, or sometimes on the rare occasion the wrong card is associated with a receiver and needs to be changed.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.