Make a subscriber identity module (SIM) , that provides some battery backup (at least for 2 minutes) for another user to whom you talking
Description: suppose you are person A , talking to person B, But in the meantime person B's mobile is switched off due to low battery, so I suggest Vodafone R&D to make such a SIM (for example for A or vice versa), so that when person A again call Person B by his/her phone (with the help of battery back up newly made SIM)can be able to provide the battery backup to person B mobile and switch on the mobile of Person B automatically and Person A can be able to talk with another user like Person B
