What is 5G? 5Gで出来る事をイラスト付きで解説!

What is 5G? 5Gで出来る事をイラスト付きで解説!

As more users come online with higher data demands, 4G networks have reached their limit. Seems we have a problem!


5G, the need

You see, depending on the technology in use, we need to get faster download and upload speeds, lower latency, more stable connections, or a wider coverage compared with what 4G can enable.


To address the increasing demand off the radio network, 5G NR (5th Generation New Radio) technology vision is roughly created as follows:



  • 1000X more traffic
  • 1000倍交通を増加


  • 10X higher data rates per user (downloading an HD movie in seconds!)
  • 10倍データ高速 (HD映画を数秒でダウンロード出来ること)


  • 30X lower latency for new demanding application (connected cars or drones)
  • 30倍低遅延 (コネクテッドカーやドローンなど)


  • 100X less power for longer battery life
  • 100倍電力を下げる (今より電池の持ちをよくするため)


  • 10-100X increased connected devices (1 million per )
  • 10~100倍IoT使う器具を増えている (1平方キロメートルあたり100万)


From the above vision, with its 1ms latency, 10 Gbit/s peak speed and ultra-reliable connections, 5G is the required technology for digital transformation, i.e., IoT, AR, VR, and connected cars.


But what exactly is a 5G network? ところで、5Gネットワークとは正確には何ですか?

The truth is, experts can’t tell us what exactly 5G is, because they don’t even know yet! But what we know is that five technologies are emerging as foundations of 5G and are as follows:



  • Increased spectrum with trend towards millimeter waves

  • ミリメートル電波(ミリ波)へスペクトル増加


  • Small cells

  • スモールセル


  • Massive MIMO (Multiple Input Multiple Output)

  • Massive MIMO(複数入力複数出力)


  • Beam forming

  • ビームフォーミング


  • Full duplex (we will not talk about this because it’s not relevant to what Tecdia does)

  • 全二重通信(これについてはテクダイヤの事業内容とは異なりますので、ここで話しません)


We will briefly discuss about the above technologies and their corresponding issues while keeping things simple.


Key technologies of 5G: MM-wave and it’s issue. 5Gの重要な技術:ミリ波とその問題について

To get more bandwidth, we open up some not-yet-used space at mm-wave (millimeter wave) frequencies. More bandwidth, means faster download and upload speeds and/or more online devices.



5G, mm-waves


Although it seems that we have solved our bandwidth problem by employing mm-wave, this solution comes with its issues. MM-waves cannot travel through buildings and they get absorbed by plants and rain.



5G, mm-waves issue


Seems we need a solution for this issue which is called the mm-wave path loss. That is, mm-waves cannot travel longer distances.

ミリ波経路損失と呼ばれるこの問題の解決策が必要なようです。 つまり、ミリ波は長距離を移動できません。

Key technologies of 5G: Small cell. 5Gの重要な技術:スモールセル

To get around mm-wave path loss problem, we need small cell networks.



5G, small cell


At mm-waves signals cannot travel longer ranges due to obstacles. Using large number of low-power mini base stations which are much closer together, small cell networks will solve that problem. That’s why the small cell network concept got introduced to 5G.

ミリ波では、信号が障害物のために長距離を移動できません。 多数の低電力ミニ基地局を使用すると、スモールセルネットワークがその問題を解決します。 そのため、スモールセルネットワークの概念が5Gに導入されました。


Key technologies of 5G: Massive MIMO and it’s issue. 5Gの重要な技術:Massive MIMO

MIMO stands for “Multiple Input Multiple Output”. It’s employed in 5G to increase the network capacity even more.

MIMOは「Multiple Input Multiple Output」の略です。 ネットワーク容量をさらに増やすために5Gで採用されています。

5G, massive MIMO

However, massive MIMO causes inter-cell interference. Because if antennas broadcast in every direction at once, as they used to do so in 4G cellular networks, we’ll have a serious interference caused by the massive MIMO.

ただし、Massive MIMOはセル間干渉を引き起こします。 4Gセルラーネットワークで使用されていたように、アンテナが一度に全方向にブロードキャストすると、Massive MIMOによる深刻な干渉が発生するためです。


5G, massive MIMO issue


Key technologies of 5G: Beamforming. 5Gの重要な技術:ビームフォーミング

Instead of broadcasting in every direction, beamforming is sending a focused power (directional antenna) to a specific user. It can be achieved by a phased array antenna which is an array of antennas with controlled input signal phase.

ビームフォーミングは、あらゆる方向にブロードキャストする代わりに、特定のユーザーに集中電力(指向性アンテナ)を送信します。 これは、入力信号の位相が制御されたアンテナのアレイであるフェーズドアレイアンテナによって実現できます。



5G, beamforming



As a final note, we will look into frequency bands of 5G. 最後に、5Gの周波数帯域を調べています。

Out of numerous frequency bands of 5G, the 3.5 GHz band is looking to be especially important as it’s likely to be globally used for the early deployment.

5Gの多数の周波数帯域のうち、3.5 GHz帯域は世界的に早期展開される可能性が高いため、特に重要になりそうです。


5G, frequency bands