cannon mx870 series

HAVING A PROBLEM WITH MY CANNON MX870, IT SEEMS TO CONTINUE TO DISCONNECT FROM OUR WIFI NETWORK / BONJOUR SO I HAVE TO REPEATEDLY HAVE TO DELETE IT FROM THE PRIBTER OPTIONS THEN ADDING IT AGAIN TO USE IT. AFTER ITS CONNECTED FOR 10-15MIN IT DISCONNECTS ON ITS OWN.... AND THIS IS A NEW PROBLEM.