One of the most innovative technologies of the 21st century is the smartphone. This device is packed with a wide range of features that allow it to do almost everything. There is one feature, however, that isn’t celebrated enough: the emergency call. For starters, the emergency call feature allows smartphone users to contact first responders even when they do not have a reception (network signal). But how is this possible? How can a phone make an emergency call without a signal? Let’s find out!
How Emergency Calls Work
To provide a clear understanding of how emergency calls work without a network signal, let’s go a little further back on how network providers facilitate this service. After buying a phone, you must register it with a network provider who provides you with a SIM card. Upon inserting the SIM card into your phone, it automatically connects you to a signal displayed on your phone’s top bar. This signal becomes stronger or weaker depending on how far you are from a cell tower.
When making a phone call, the signal on your phone connects to a nearby cell tower and relays it to the next tower until it reaches the person you’re calling. This is a seamless process that occurs in seconds.
However, when a phone has no signal, the emergency call feature allows networks to bounce off the nearest tower, even if it belongs to another provider. Unlike conventional calls that can only be relayed through the towers of a specific provider, emergency calls are designed to bypass this hurdle.
Network providers put competition aside during an emergency and work together for a common goal: helping the one in distress. This makes it possible for emergency calls to always go through, even if your provider does not offer network coverage in that area.
How Enhanced 911 Can Facilitate Emergency Calls
Another factor that facilitates emergency calls without signals is E911, which stands for Enhanced 911. This concept is available in the Cayman Islands, Mexico, Canada, and the United States. Local regulations in these countries require that all cell phone towers be equipped with enhanced 911 receivers, even the decommissioned ones.
Also, there is a strict policy that all providers accept 911, even if the user does not have a phone plan. This concept dates back to the era of GSM in the 90s when anyone could make an emergency call without a service.
The best part about E911 is that it’s more upgraded. Not only does it accept 911 calls, but it also provides a report of the caller’s location. This makes it easier for first responders to track callers whose phones may have been switched off or snatched by whoever is attacking them.
Do Emergency Calls Always Go Through?
Most people don’t understand that network providers often share cell phone towers. Some may even rent towers from other companies. Be as it may, there is something called network provider authentication that plays a crucial role in emergency calls. This feature allows mobile phones to transmit signals across a particular network.
Network provider authentication is mainly limited to a specific region, such as a particular country. This is why an emergency call may not go through if you are in a different country. The only exception is if your carrier also offers services in that country. That’s why it’s advisable to always get a local SIM card upon landing in a foreign country.
As long as the local network providers have no contract with your carrier, they will not let your emergency signal go through. This can be pretty dangerous, especially in accidents or ambushes.
Can You Make an Emergency Call Without a Sim Card?
Modern smartphones can make emergency calls even without a SIM card, let alone a signal. The second you dial an emergency contact such as 911 or 999, the phone’s software immediately identifies this as an emergency and looks for available network towers. This is one of the measures enforced by the 911 Act.
Pro tip: when emergency calls fail when connected to a particular carrier, switch the phone off and on and then make a call without keying in the pin. This will be considered as a SIM cardless emergency call. The call should go through even if your carrier is experiencing some disturbances. Another tip is to make an emergency call using someone else’s phone. You don’t have to know their PIN or lock screen pattern to do this.
Regarding emergency calls, priority is given to anyone in need, whether they have a SIM card or not. With the upgrade of E911 and the introduction of better communication systems such as 5G, emergency calls will be easier to make.