The  number of mobile phones in the world is almost double the number of humans. That’s actually easy to understand, given the fact that you most likely have a mobile phone and you definitely know someone who uses two or three phones. As many as they are, phones do not talk (at least, not in the way we think).

That is not to imply that mobile phones never communicate directly. Wired and wireless technologies such as infrared, Bluetooth etc. make that very possible. What I’m stating is the fact that a mobile phone does not actually call another mobile phone directly. It has to go through a network mast. I know you’ve seen network masts around. They look like the one below:

To put this in the Nigerian context now, there are a few phrases almost all of us have memorized already:

  • “The number you are trying to reach is not reachable at the moment, please try again later…….”
  • “The number you are trying to call is not available, you can leave a message at regular call charges……..”
  • “The number you are calling cannot be reached………”

Whichever of the above messages (or their variants) we get from network providers when trying to make a call, we do know that the person’s phone is most likely not switched off. For some reasons ( reasons that are not actually as strange as we think), the destination cell phone just can’t be reached. Most people who think these messages can only be caused by long distances between caller and recipient are usually stunned when they perform the simple experiment of calling two mobile phones side by side and sometimes still getting the “not reachable” statement. It makes you wonder what is actually happening when you make phone calls. Let me explain.

Can Phones call Each other?

Technically, yes. The exact same way walkie talkies work ( you might be familiar with that). A walkie-talkie is simply a two-way radio. Multiple devices operating on the same frequencies. If you know a thing or two about walkie talkies though, you will know that:

  1. Only one person can talk at a time.
  2. Someone else could easily tune in to the same frequency on their radio and listen to your entire conversation.
  3. They are highly restricted by range. That means they can’t cover much distance.
  4. Sound is usually not very clear as there is a lot of static interference.

How phones connect

Reasons number 1 and 2 are the major reasons cellphones cannot be made to work like walkie talkies, which is why, no matter how close phone are physically, a call from one phone cannot go directly to the other phone. It has to pass through a mast. By definition, Cellphones (also known as cellular phones and, chiefly in Europe, as mobile phones or mobiles) are radio telephones that route their calls through a network of masts linked to the main public telephone network. I’ll let you figure that out with this diagram:

So, when you dial a number on your mobile phone, the signal goes from your phone to the nearest telephone mast, then to another telephone mast/base station, then another, and another, and the next, until it gets to the mast nearest to your called phone.  Sometimes, signals jump through hundreds of masts ( and more) to get to their destination. SMS (Short Messaging Service) and  Bulk SMS platforms (such as LoftySMS )  go through the same process before delivering messages to your phone. Only mobile internet does not follow suit.

If you look at this scenario, there are potentials for so many things to go wrong along the way. Signals get lost, lines and voices get scrambled, sounds get gabbled, etc. It doesn’t happen every time, but it certainly does.

The cause of the problem

When call signals can’t get to their destinations, it’s usually because of some factors such as:

  • Heavy rainfall : Water reflects radio waves, therefore, your call signals might find it difficult to even leave your vicinity.
  • Storms: Masts can get damaged by heavy winds. Though they are designed to easily fallback to the nearest option, multiple damages to multiple masts in a particular location will lead to very poor or no cell signal
  • High Call Traffic: This usually happens around festive periods when the volume of calls made go up astronomically. When a masts capability is stretched to the limit, it has no choice but to put your call on hold till space frees up for it to go through. That’s when you usually get the cryptic message “Network Busy”.

The hope..

Nobody likes it when their calls don’t go through, and for Nigerians, I have good news concerning this. A new network provider ( M7tel ) is coming soon with the technology and infrastructure to eliminate all the network issues in Nigeria telecommunications.  Soon as it launches, I’m very sure that “numbers not reachable/available” will be a thing of the past in Nigeria.

To conclude, there  are many factors & technologies surrounding phone communication. This article has hopefully summarized a few of the basics that you need to know. So, the next time your phone says “The number you are calling cannot be reached”, you have an idea of what’s going on.





Samson Okemakinde

The author Samson Okemakinde

Techie since 2010. Awesome at computer programming, music, writing and Logic. Typical Ibadan boy with a B.Sc in CSC from UI, plus a range of diplomas, certifications and cutting-edge skill sets in diverse areas including web development, android application development, public speaking, leadership and management, security cameras, satellite installations, etc.

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