No matter which flight your on call bells are their for both pax use and emergency. Having worked a full gulf-dac flt where the call bells were part of the light show, however inflight as long as cabin crew patrol the cabin and I am not saying that we dont, but my last airline they thought it was time to sit chat drink coffee etc and forget about who pays our wages and being the senior crew I would make sure they patrolled the cabin with trays of drinks every 30-45 mins