User is active throughout the session in my web application

I have a web application whee login user attention is required.

Now my scenario is if UserA is login through chrome browser and open 5 tab in that same session for UserA. I might check active tab must have at least mouse activity.

I manage it through javascript. But when I'm on tab2 and actively working on that tab2, my tab1 expired the session after amount of time I decided.

I need if user active on any of the tab, it considered as attended and active.

Ex. 1.UserABC login via chrome tab1 2.Javascript started on that tab1 and count for 20 min. If no activity found session time out. And UserABC must relogin.

Scenario 1.UserABC login via chrome tab1 2.Javascript started on that tab1 and count for 20 min. 3.UserABC session open tab2 for same website page. And work on tab2 for next 20 min. 4.When 20 min. reached tab1 expire the session because no activity done on tab1.

I tried to store this on server side for another work-around but in that website performance is down(obviously).