My kid is only 1.5 year old but still he knows what Mobile means ( a Toy that have visual and sound both and yes he knows where i usually keep my mobile) . I followed simple rules to cut down his mobile activity.1. Start spending more time to play with him with his Toys/ Coloring book/Stacking games 2. Make a routine to go morning & evening walk and playing in garden with him.3. I changed my mobile location from the usual one and keep the ringing volume in LOW mode.Now he forget the Mobile time without even knowing that he missed something in his routine activity.