Okay, so at a high level, we all know what a mobile network is – it’s a communications network that allows us to wirelessly communicate with our friends, family and colleagues. That, to many, is a sufficient explanation, but I want to go a little bit deeper.
There are a few core components that make up a mobile network:
- Base stations / cells
- Core circuit switched network
- Packet switched network (for mobile data)
- PSTN (Public Switched Telephone Network)
Base Stations / Cells
A mobile network is distributed over land areas called cells – served by a cell site. Each cell uses different frequencies to avoid interference. It should be noted that frequencies can be reused by cells that are not directly adjacent (as the same frequencies being used in close proximity can cause interference).
When cells are joined together, they provide a mesh of cells over a wide geographic area, providing consistent network connectivity to a wider audience.
As a user moves through the geographic areas, there is a handover between cells, ensuring uninterrupted coverage of their mobile signal.
Cell sites vary in coverage areas:
- 10 metres (Femtocell)
- 200 metres (Picocell)
- 2km (Microcell)
- Cell sites in can range from 800m to 40km (depending on how built up the area is).
Core Circuit Switched Network
The core circuit switched network handles the core functionality of the mobile phone network. It deals with:
- Routing of voice calls
- Routing of text messages
- Mobility and handover of calls when the user is in transit
- Charging & real time pre-paid account monitoring
Packet Switched Network
GPRS (General Packet Radio Service) allows 2G, 3G and 4G to transmit IP packets – enabling data transfer and internet connectivity. This enables: SMS, MMS, Internet access and plenty more.
To put it simply, packet switching is the routing and transfer of data packets. These packets are addressed with a destination IP and plenty more information, as outlined in another article, here.
I will discuss this concept further in a later article.