How do 5G mobile communications work?

Remaining accessible in the car, making a video call while you’re on the move, sending photos while on the train – and doing it all wirelessly. Did you ever wonder how that works? Read on for an explanation of the fundamentals of mobile communications – and find out what’s so special about the new generation.

To grasp the basic principles of how 5G mobile communications work, we have to start with the fundamentals. A mobile network consists of 

• a network operator’s core network, connected to the Internet, 
• the transmission network that connects the core network to the radio-based access network (base stations) and 
• the devices operated by users (mobiles, tablets or networked sensors). 

The area supplied by the transmitting antennas of a base station is known as a radio cell. To engage in mobile communications and data exchanges, users have to be within one of these areas. 

Depending on where it is deployed, the radius of a mobile radio cell can cover an area of a few metres up to a number of kilometres. Key factors include the transmitting power, the frequency used and above all to what extent the area supplied by the network is built-up. 

In locations that see high levels of use – such as pedestrian precincts, airports or trade fairs – the radio cells are as a rule smaller. They range from just a few hundred metres in size right down to just 10 metres. Compare this with areas that experience relatively low levels of use, where the cell size is much larger and can even extend up to 70 kilometres. 

Turning text into signals and signals into texts 

Here is a simplified illustration using a message as an example of how information travels from one mobile to another:

How 5G is different 

The fifth-generation mobile communications standard (5G for short) is an evolution of previous mobile communications – the successor to the GSM (2G), UMTS (3G) and LTE (4G) standards. In these initial stages, the 5G network is making extensive use of the infrastructure of the LTE network. The two networks run together or in parallel, allowing the expansion to happen step by step. However, there is a difference: the new technology sets new benchmarks in respect of 

• higher data rates, 
• faster reaction times, 
• increased reliability, 
• increased user mobility, 
• increased network capacity and 
• improved data security. 

The availability of 5G mobile technology hinges on the network planning of the individual mobile network operator. 5G technology is being built up steadily, but to varying degrees of intensity. This depends on the expansion strategies of the respective companies. The process can differ from one region to the next. 

It all comes down to frequency 

For data to be transmitted wirelessly between mobile phones and base stations, electromagnetic waves with particular frequencies are necessary. Frequencies are not just needed for mobile communications, but also for all other kinds of radio communications system – such as Wi-Fi, radio broadcasting for radio and television, satellite broadcasting, baby monitors or garage door openers. 

The current mobile technologies use frequencies in the range between 800 megahertz and 2.6 gigahertz (abbreviated as GHz). With 5G, further ranges of higher frequencies are added: 3.4 to 3.8 GHz, with frequencies in the significantly higher range from 24.25 to 27.5 GHz still to come – the so-called 26-gigahertz range. Essentially, there are two groups of frequency ranges, each with different characteristics as regards propagation performance. 

Frequency range below 1 GHz: 

• These radio waves have a high level of coverage. 
• They can more easily penetrate many materials found in buildings. 
• This frequency range is less suited to the transmission of large volumes of data. 
• Such frequencies are however especially suitable for covering dead spots, particularly in sparsely populated regions. 

Frequency range higher than 1 GHz: 

• The coverage of these radio waves is lower than that offered by frequencies below 1 GHz. 
• Their behaviour is almost identical to that of light: they can be absorbed and even reflected by many materials. This effect increases at higher frequencies. 
• The higher the frequency range, the greater the availability of frequency bandwidth and the higher the data rate. 
• Frequencies of 2.5 GHz and over are suitable for cities or industrial sites, though it should not be assumed that their use is widespread. 

The fact that the “old” frequency ranges are also used for 5G means it is possible to provide comprehensive coverage with the new mobile communications standard in a manner that meets the needs of the respective area. Technical innovations such as active antenna technology (beamforming) and division into application-specific networks (network slicing) are further improving the mobile network. For a comparison of the different generations of mobile communications, please see this article.

article.sources

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2. Bundesamt für Strahlenschutz (BfS). Mobilfunk: Fragen und Antworten. [31.05.2024].
3. Deutsche Telekom. Was ist 5G? Grundwissen zum Mobilfunkstandard. [31.05.2024].
4. Telefónica Germany. So kommt 5G zum Funkmast: Glasfaser und Richtfunk sorgen für schnellen 5G-Ausbau. [06.11.2023].
5. Vodafone GmbH. 5G: Das Echtzeit-Netz für die Zukunft. [09.05.2023].
6. Deutsche Telekom. Mobilfunk und Gesundheit.  [17.06.2024].