From a subscriber’s perspective, making a phone call is a simple action. But after many years in the telecoms space, Ibikunle Peters understands just how critical calls are and the complex mechanics that make them possible.
He explains why connectivity must be up and running at all times. “Imagine the whole of the MTN network goes down, and people can’t make calls. A lot of panic will ensue across the country,” he says.
Peters has spent more than a decade as an IT and telecoms infrastructure expert working to ensure such panic does not occur.
What he describes simply as “keeping the lights on” is, in reality, a far more complex process. “When you pick up your phone to make a call, it is an entire value chain,” he says. Ensuring you have network coverage, good call quality, and that you are charged the correct amount all fall within his remit.
Much of Peters’s more than ten-year career was spent at Huawei, where he worked as a billing application engineer for over nine years. He has also worked at Airtel and 9Mobile (now T2 Mobile) over the years.
What happens behind the scenes when you make a phone call
Peters offers a crash course on telecoms infrastructure and how it works. “A lot happens when you pick up your phone and call someone. A key part of that process is the mast”
He explains that cell towers or masts — technically known as base transceiver stations (BTS) — play a vital role in the voice call process.
He likens them to Wi-Fi routers, strategically placed to serve people within a specific area. However, if you are too far from one, your signal weakens. Just like a router, the closer you are, the better your connection.
But these masts do not operate in isolation. They need to communicate with one another, which is where the base station controller (BSC) comes in.
Even then, connectivity alone does not guarantee a smooth call. While the masts may be connected and the signal strong, the system still needs to know who you are and who you are calling — a task handled by a system known as the home location register (HLR).
The HLR helps identify who is calling whom. “It is your database,” Peters explains. “It holds information about when you were registered, the base station serving your call, and the person you are trying to reach.”
Another key function of the HLR is determining whether a call is made within the same network or across different networks, for example, an MTN-to-MTN call versus an Airtel-to-MTN call.
According to Peters, the technical terms for these are on-net calls (within the same network) and interconnect calls (between different providers).
The HLR also performs number analysis. “It checks whether you are within or outside the country to determine the applicable call rate,” he says. This analysis applies to both the caller and the receiver. The receiver could be a toll-free number or even a number you are restricted from calling.
Beyond these, several other systems work together to ensure that something as simple as a phone call just works. Some of these systems also help telecom operators remain compliant, sharing required information with the Nigerian Communications Commission (NCC) and ensuring call rates are correctly applied.
Source: techpoint.africa
