How Emergency Calls Work

You might ever try to call anyone when there is no balance in your mobile phone or without inserting any SIM card. Surely you will not able to connect to call. But you may not know this fact that you can dial emergency call without any balance or SIM card in some countries like India. But how it is possible without any SIM card? One need SIM card in order to make any call from his mobile phone. Let’s know how SOS call actually works without any SIM card.

First we have to know how normal phone call works then we will know does SOS call works.
To make calls you need SIM card with minimum balance. When you dial phone number from your phone, your phone's antenna send signal to the nearest tower then tower sends your call request Mobile Switching Center (MSC). Mobile Switching Center is place where your SIM information is registered then it will check your phone and your target phone information like location, balance, etc. Then call is successfully made possible. If you want detailed explanation of how mobile phones call works then let me know.

SOS calls are already allotted in your mobile phones. So your mobile knows that you can still dial emergency number without SIM card. The similar process of making call is followed but due to emergency your request is bypass to nearest emergency service station. You may not able to make call if you are far away from the tower range. This is the reason why one is not able to make call in deep forest. But you have question that how that call is being traced if no mobile number is displayed to them.

We know that nearest tower receives the signal from your phone antenna. And each tower is connected to other tower in order to transmit your request. To trace the location of the call triangulation method is used. In area there are multiple towers from that 3 nearest towers are referred, each tower gives the range of the call. For example 1st tower tells caller is 3 km away from it, 2nd said it was 5 km away and 3rd said 2 km. From this data they get the callers area location but not exact location but why? Well this is the limitation of tracing. Only GPS tracing tells the exact location of the caller. We hope that 5G will overcome this limitation.

Most of the modern Android phone provides feature of instantly dialling the SOS number by clicking power button 3 times in row. If it is not enabled you can simply enabled it from the setting. But this feature may get you in trouble sometimes.