# What is 5G?
###### tags: `Guide book`

(source: [Erricson](https://www.ericsson.com/en/5g), [Qualcomm](https://www.qualcomm.com/5g/what-is-5g))

5G is the fifth generation of cellular networks. Up to 100 times faster than 4G, 5G is creating never-before-seen opportunities for people and businesses. 5G wireless technology is meant to deliver higher multi-Gbps peak **data speeds**, ultra **low latency**, more **reliability**, massive **network capacity**, increased **availability**, and a more uniform user experience to more users. Higher performance and improved efficiency empower new user experiences and connects new industries.

Faster connectivity speeds, ultra-low latency and greater bandwidth is advancing societies, transforming industries and dramatically enhancing day-to-day experiences. Services that we used to see as futuristic, such as e-health, connected vehicles and traffic systems and advanced mobile cloud gaming have arrived.

With 5G technology, we can help create a smarter, safer and more sustainable future.

# Evolution of 5G
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Things have changed a lot since the first generation of mobile technology.

- The **1G** era was defined by briefcase-sized phones and short conversations between a relatively small number of professional people.
- In the lead up to **2G**, the demand for mobile services grew and never slowed down.
- Phones that could fit in your pocket, SMS and mobile internet access were hallmarks of the **3G** world.
- Thanks to **4G**, we have smartphones, app stores and YouTube.
- Now, **5G** is completely reshaping both our professional and personal lives by enabling new use cases like connective vehicles, Augmented Reality and enhanced video and gaming.

# Components of 5G
(source: [5g.systemsapproach.org](https://5g.systemsapproach.org/arch.html))
The cellular network provides wireless connectivity to devices that are on the move. These devices, which are known as User Equipment (UE), have traditionally corresponded to smartphones and tablets, but will increasingly include cars, drones, industrial and agricultural machines, robots, home appliances, medical devices, and so on.


As shown in the figure above, the cellular network consists of two main subsystems: the Radio Access Network (RAN) and the Mobile Core. The RAN manages the radio spectrum, making sure it is used efficiently and meets the quality-of-service requirements of every user. It corresponds to a distributed collection of base stations. As noted above, in 4G these are (somewhat cryptically) named eNodeB (or eNB), which is short for evolved Node B. In 5G they are known as gNB. (The g stands for “next Generation”.)