5G(5th Generation:第5世代)についてご紹介します。まずは求められている要件についてですが、大きく分類すると、超低遅延・超高速・多数同時接続となります。具体的には、(4Gと比較したときに)システム容量1000倍・接続機器数100倍・ピーク速度10Gbps・遅延1ms以下・低消費電力化が必要となります。数字だけみると、とても実現できそうにないように思えてきますね。

 I will introduce about 5G (5th Generation: 5th generation). First of all it is a required requirement, it will be ultra low latency, ultra high speed, many simultaneous connections when it is broadly classified. Specifically, (when compared with 4G) it is 1000 times the system capacity – 100 times the number of connected devices – Peak speed 10 Gbps – Delay 1 ms or less – Low power consumption is required. Looking at only value, it seems not to be realized very much.


 Of course, not all scenes must realize these, but the performance required by the scene being used is different. For example, since LPWA is equipped with communication modules in everything, it is necessary to “increase the number of connected devices” and “reduce power consumption”, and in V2X it is necessary to accelerate risk prediction and response, so “low delay” and “peak Speed improvement “, VR / AR is said to require” system capacity increase “because 4 k video delivery will result in huge traffic data communication.


However, in order to realize each requirement, obviously there is a difficult part with extension of the conventional technology. So next time I would like to introduce breakthrough technologies to realize these.





 One of The technology repuired breakthrough is expansion of communication data capacity. By the way, do you know what the data capacity is decided? Some people may think that the speed will rise as the frequency increases from the well-known physical wave formula. But it is a mistake, actually it is determined by the value bandwidth. In the initial setting such as WiFi, you think that it will be selected as 2.4 GHz band or 5 GHz band, but in fact there are 14 channels with a bandwidth of 22 MHz, from which there is a total of 14 ch and the data communication speed is determined by this wide bandwidth . Please think that it is an image like the size of the basket containing the data.

しかしながら、SHF(Super High Frequency:センチメートル波)と呼ばれている周波数帯までは、様々な規格によって既に占有されている状況で、5Gで掲げられている帯域幅1GHzほど確保できる十分なリソースは当然残されていません。そこで未だ利用されていない、より高い周波数であるミリ波帯(30~300GHz)にスポットが当たっている訳です。

 However, up to the frequency band called SHF (super high frequency: centimeter wave), in the situation already occupied by various standards, enough resources that can be secured about 1 GHz bandwidth listed in 5 G are Naturally it is not left. That is why the spot hit the millimeter wave band (30 – 300 GHz), which is a higher frequency not yet used.


 Basically, as the frequency band becomes higher, the energy loss on the board etc is higher / Measurement accuracy is also in the direction such as difficulty, so the measurement system will also become high cost. However, It is one of technologies that want to advance development for the no frustration such as animation and software installation and AR in the all street. Next time we will introduce Mimo, a secret weapon for many simultaneous connections, good compatibility with millimeter waves.




MIMO(Multi-Input Multi-Output)は、言葉通り入出力が多いという意味で、通信機器において入出力端とはアンテナを指しています。そう、MIMOとはアンテナ数を増やす技術のことで、送信機と受信機に複数のアンテナを設置します。

 Well, I would like to introduce MIMO (Multi-Input Multi-Output). In communication equipment, I / O terminals refer to antennas. MIMO means that there are a lot of antennas, and we will install multiple antennas at the transmitter and the receiver.

MIMOを用いることによって、帯域幅や通信出力を増加することなく、通信速度を高めることが可能となります。これは、データを入れるかごの大きさを増やすのではなく、かごの個数を増やすイメージです。現状、LTE Adevancedにて最大4つのアンテナを使うMIMOが導入されています。

 Using MIMO makes it possible to increase the communication speed without increasing the bandwidth and communication output. This is an image that increases the number of baskets rather than increasing the size of the cage that contains the data. Currently, MIMO that uses up to 4 antennas at LTE Adevanced has been introduced.

そして、5Gで導入されるMIMOはMassive MIMOと呼ばれており、基地局でのアンテナ数が飛躍的に多くなります。これまでは、基地局と通信機器(携帯端末等)間での通信において処理待ちの機器が発生し通信速度が遅くなる問題を、アンテナ数ひいては入出力数が増えることで解決することができます。これは、スーパーマーケットでレジの数が増えるイメージしてもらえると分かりやすいかと思います。

 MIMO introduced in 5G is called Massive MIMO, but the number of antennas in the base station will be dramatically increased. It is possible to solve the problem that the communication waiting time occurs in the communication between the base station and the communication device (portable phone etc.) and the communication speed becomes slow, by increasing the number of antennas. I think that this is easy to understand if the number of cash registers increases at the supermarket.


 Why this kind of thing is possible, that is improvement of directionality and development of beam forming technology. As 5 G uses frequencies as high as several tens of GHz, radio waves lose diffraction and propagate linearly. This allows you to concentrate energy in one direction, which in turn leads to improved directivity. And beamforming is a technique that determines the direction in which direction is given, it is an image aiming at the direction of the communication device of the other side. However, here, not only the base station, but also the other side terminal needs to have a function.


 Although it was an introduction about MIMO, it is terrible to use millimeter waves used in satellites on mobile terminals if you think carefully. Considering the needs for the user’s communication speed, I think whether the area is limited here, but I would like to experience communication with submillimeter waves before I die.