In today’s busy world we spend a lot of time on our smartphones for various activities including phone calls, messages, social media, online videos and possibly many others. Our smartphones allow us to stay connected with our family and friends no matter where in the world we are. This mobility aspect is exactly what makes our mobile phone our most reliable digital companion that keeps us connected to the outside world. The reliability, however, does depend on which mobile cellular network you are on and how good the coverage of that network is. Let’s find out what a mobile cellular network looks like and how it really works.
A cellular network or mobile network is a telecom network that uses radio waves to create nationwide wireless coverage for mobile devices e.g. smartphones. It employs cellular technologies such as GSM, UMTS, CDMA2000, LTE and NR to create ‘mobile wireless’ connectivity so that the devices can stay connected wirelessly even when they are moving.
What is a cell?
A cell is basically a network coverage area created by the transmission and reception of signals from a mobile base station. The place where a mobile base station is installed is called cell site. Mobile operators use a large number of cell sites to provide nationwide coverage to their customers. The cells are formed by the antennas installed on the site that radiate radio signals that form network coverage in any given area. These antennas are powered by electricity and this power determines how far the radio signal can travel. The higher the power, the longer the signal can travel. These signals are sent at certain frequencies so that they don’t interfere with signals coming from other base stations. Only the mobile phone that the signal is intended for can decode that signal based on the digital techniques used by mobile operators. The frequency also determines how far the signal can travel; lower frequencies travel much further than higher frequencies.
Mobile operators use a large number of base stations through a country. If you are on a phone call and start moving away from the range of the cell that is serving you, your call can be handed over to the next nearest cell that is available. This way, the mobile network makes sure that you stay connected when on the move so that your calls (or any other services) can continue without any interruptions.
Who manages the base stations?
The cellular base stations are owned by the mobile network operators such as Vodafone, T-Mobile, Rogers etc. Different terminologies are used for base stations depending on the generation of mobile communication e.g. 2G, 3G, 4G etc. In 2G GSM (Global System for Mobile) networks, the base stations are called Base Transceiver Station or BTS. In 3G UMTS (Universal Mobile Telecommunication System) networks, the base stations are called Node B and in 4G LTE (Long Term Evolution) networks they are called eNodeB.
The base stations represent the radio part of the mobile network, and one base station typically contains multiple cells which operate on specific radio frequencies. These base stations are deployed in large numbers within any geographical areas such as towns and cities. The radio network is what connects a mobile phone to the mobile network. When you are using your mobile phone to make a call, it is the radio network that your phone communicates with first. The radio network then connects your phone to the other parts of the mobile network and/or any other external networks. Let’s have a look at the simplified network diagram below to visualise this concept.
As we may be able to observe from the simplified diagram above, the mobile core network is a central part of the mobile network that allows mobile subscribers to use all the services that they are entitled to. It provides vital functions such as subscriber profile information, subscriber location, authentication of services and the necessary switching functions for voice and data sessions.
Both the radio and core networks have evolved considerably with the evolution of mobile networks from 2G to 3G, 3G to 4G and then 4G to 5G. If you are looking for more information on the radio and core networks, please search for these on our site.
Digital and analogue cellular networks
While today, we are all digital but it wasn’t like that from the beginning. The first generation of mobile networks (1G) in the early 1980s used analogue technologies. These mobile networks were deployed in different parts of the world using various analogue standards. The most popular standards were Advanced Mobile Phone System (AMPS), Nordic Mobile Telephone (NMT), Radio Telephone Network C (C-Netz) and Total Access Communications System (TACS). Analogue communication systems are usually more sensitive to noise in the air interface, which deteriorates the clarity of the speech. They also lack encryption capabilities, which makes them more vulnerable to security threats.
Analogue networks were followed by digital networks in the early 1990s which marked the beginning of the type of mobile networks we see today. Digital systems are much more resilient to noise and offer much higher security levels as compared to their analogue counterpart. The second generation of mobile networks employed various digital standards. The most popular standards are Global System for Mobile Communications (GSM), Digital Advanced Mobile Phone System (D-AMPS), and Interim Standard 95 (IS-95, proprietary name: cdmaOne). The third, fourth and the fifth generations of the mobile networks (3G, 4G and 5G) are also digital.