What is 5G ?


What is 5G after all?  What’s so great compared to LTE ?

With the Rugby World Cup being held this year in 2019 and the Tokyo Olympics scheduled to take place, the word”5G”has recently become more familiar than before, ahead of these major events. So what is the often said”5G”? What’s great compared to 4G so far?

5G is the “5th generation” of mobile communications technology. Mobile phones/technology has been developed based on the global standard (3GPP) and the fifth generation of this innovation is 5G.

For reference, the technologies from the 1st generation to the 4th generation so far are listed below in Japan.

Generation of Cellular technology

1st Gen: HiCAP, TACS, AMPS, etc.
2.5th Gen: cdmaOne
3rd Gen: WCDMA,CDMA2000
3.5th Gen: HSPA,HSPA+,CDMA2000 1xEvDO
3.9th Gen: LTE,WiMAX,UMB
4th    Gen: LTE-Advance,WiMAX2

5G is not an extension of 4G LTE

We’ve found that 5G is the fifth innovation, but what’s great about this fifth-generation technology? So far, download speeds have improved with 3G, 4G,and 5G, but does5G only improve download or upload speeds even more than 4G LTE-Advance and WiMAX2? The answer is “NO”.

5G certainly improves the download/upload speed significantly, but it is one of the features of 5G, and there are several other features. Rather, features other than high-speed communication are important in 5G.

In the 3GPP standard, 5G defines three characteristics:

5G Characteristics

1) High-speed, high-capacity
Enhanced Mobile Broadband (eMBB)

2) Ultra-low latency and reliability
Critical Communications (CC) and Ultra-Variable and Low Latency Communications (URLLC)

3) Massive and multiple device connections
Massive Machine Type Communication (mMTC).


5G lets you download movies in 2 seconds

5G has new features such as ultra-low latency, reliability, and mMTC that have never been before other than high-speed and high-capacity communication. Let’s take a look at what each feature looks like.

Enhanced Mobile Broadband (eMBB)

High speed and large capacity is that the communication speed is dramatically faster. How fast is 4G LTE-Advance downloaded up to1.2Gbps in Japan using new technologies (carrier aggregation), but at 5G it’s up to 20Gbps!

20Gbps is more than 15 times faster than 4G in numbers, but how does it change in real life? For  example, if you download a two-hour movie with a data size of about 1.5GB, 4G would take about 10 seconds to download the movie, but 5G would download it in just one second.

Wouldn’t 4G be enough if it takes 10 seconds to download a 2-hour movie? Didn’t you think? But in fact, it’s not that fast to download. Why is that?

The download speed that the carrier publishes in the pamphlet and the homepage becomes a theoretical value. However, in a normal environment, the download speed is not actually as high as the theoretical value, and even half of it is better.

The reason why this is because the download/upload speed depends heavily on the environment. For example, in urban areas, a large number of people gather in the same area, and when many of them communicate at the same time, the communication speed decreases dramatically. In addition, radio interference occurs in the city, that is, multiple radio waves such as radio waves coming directly from the nearest base stations and radio waves from neighboring base stations are mixed, which can slow down communication speeds.

Similarly, 5G is likely not to be as fast as the theoretical value, but even if it is half of the theoretical value, you can expect a speed of 10Gbps. For 4G, we compare the speed of each carrier on various Web sites, but as far as we can see, it is up to 300-400Mbps and on average 100-200 Mbps in Japan.

If you compare the download time of the movie again for two hours at this real-world download speed, it takes less than two minutes for 4G, and less than two seconds for 5G. When you come this far, you feel a good difference, don’t you? And now that high-quality video 4K/8K is getting more attention, 4G can no longer compete with these high-quality content when it comes to the mainstream.

In this way, 5G high-speed and high-capacity communication can be expected to communicate at an order of magnitude, and as a result, it is expected to be used not only in smartphones, but also in various ways, such as by replacing home optical lines (broadband) and corporate leased lines.

Ultra-low latency and reliability(URLLC)

Ultra-low latency and ultra-fast reliability are major features of 5G. 4G also achieves a reasonable low latency, so voice over LTE (VoLTE), a voice service in 4G, can be used without any discomfort, such as latency, but 5G improves this delay by an order of magnitude.

In 4G, there is a delay of several hundred millisecond at end to end, but for 5G it is much shorter than about 50ms. In 4G,the connection latency for the radio interval was large, but in 5G, the latency of this interval is greatly improved to achieve a low latency.

A delay of several hundred millisecond in 4G is not such a big problem, but what are the benefits of keeping it to a delay of about 50ms? The most expected low latency of about 50ms is remote control. Latency is very important for remote control.

For example, when a drone is operated with a controller at hand, an operational command is sent to the drone body in near real time, and the drone body operates according to the operation instruction. In this way, when you operate something remotely, you have to communicate the operation contents in “real time”. If there is a delay of several hundred millisecond, the operability will be lost and the drone will crash.

5G allows end-to-end to a delay of 50ms, which allows remote control over a 5G network. This makes it possible, for example, to operate snow blowers in hazardous areas from a centralized control room, remotely perform surgery on patients in depopulated areas, spray pesticides on fields using drones while at home, and support autonomous driving.

With ultra-low latency and reliability, 5G is expected to have many new use cases that are completely different from what previous cellular networks have not been able to do.

Massive Machine Type Communication (mMTC).

This will be a feature for IoT. Speaking of IoT, 4G is already available, but what’s the difference compared to 4G? That’s the number of terminals that can be connected at the same time.

Currently, most cellular networks are used by smartphones, but in the future, various things such as cars, surveillance cameras, factory machinery, pets, TVs, refrigerators, etc. will be connected to the network, and more terminals will be expected to access the network than ever before. Multiple terminal connections are required to support this.


5G has already started in Japan and many countries in the world

5G has started commercial services in South Korea, the United States, and Northern Europe in 2018, and since the beginning of 2019, it has been launching a number of services, including Australia, Italy, Spain and the Philippines. Japan is a little behind the world, however it was launched in March, 2020.

Japanese telecommunication companies Docomo, KDDI(au), and Softbank has been aggressively developing the 5G base station and each company have a plan to achieve 10,000 base station by middle of 2021.

In the future, as 5G infrastructure development progresses, it is expected to be used in a variety of use cases, unlike previous 4G.