I do work in security and here is the definition from NIST (national institute of information tech).
I always like to understand how things are validated, and NIST does just that for 5g
Entirely new devices and approaches are needed for 5G. That’s because many 5G systems will operate at much higher (millimeter wave) frequencies and offer more than 100 times the speed and data-carrying capacity of today’s cellphones, all while connecting billions of mobile broadband users in ever-more-crowded signal environments. NIST is focusing mainly on this category of 5G technology.
Industry’s first 5G standards, ratified in late 2017, define technologies for the use of frequency bands up to 52.6 gigahertz (GHz). Today’s cellphones operate below 3 GHz. By using new frequency bands over 3 GHz with efficient advanced technologies, 5G systems will help optimize the use of the electromagnetic spectrum, a
scarce resource.
Forecasts call for 5G wireless to transmit voice, data and images in many new ways. For instance, cellphones may talk to each other directly, with their signals skipping base station antennas on cell towers entirely. Base stations, the network hubs that receive and transmit signals, may serve a high density of short communications links in many directions.
Signal strength and frequency may be varied much faster than they are today, and specific bands of frequencies may be allocated to different categories of users at different times. “Smart” antennas may choose different directions for transmitting and receiving data, or form beams to track moving users, to help expand channel capacity and extend range.
The development of these technologies will support not only future cellphones and public safety radios but also wearable devices, the internet of things, the smart grid, smart homes, next-generation automotive technologies and smart manufacturing.
https://www.nist.gov/topics/advanced-communications/what-5g
What will be measured when testing:
- Signaling and overall performance of transistors that operate at millimeter wavelengths
- New wireless channel models
- Antenna beam forming, beam steering and over-the-air performance
- New methods and tests to evaluate device performance and minimize interference.