Welcome to jammer-buy buy this desktop cell phone jammer.
Install the cell phone jammer system, disable the cell phone entering the prison, and return the body search after each visit.
Remove the canteen system and grocery system and check the procedures received from the outside. Dining room and a grocery store system just to buy a prison of peace, by making those who have the economic ability to gain more comfort (especially food), not equal to improve the number of prisoners. Countries in charge of accommodation and food for prisoners cannot guarantee such fundamental inequalities.