Cell phones are not allowed in any DOC facility with the exception of the facility Wardens. As for Blocking the signal, there are devices made to do this but the FCC has told the state that they cannot be used. Part of the reason is that many of Oklahoma's facilitys are located in or near township and residential areas which means that if a signal blocker is used, it will also effect those areas around the facility. If you find a facebook page with an Oklahoma inmate on it, I would encourage anyone to contact the facility direct if you can tell which one it is or contact DOC's internal affairs in Oklahoma City and give then the URL for the site.