Behind the scenes "SQAT" that supports "au 4G LTE that is uninterrupted even on commuter trains"

"SQAT" aiming for an absolutely uninterrupted network

Mr. Miyao au is working to resolve dissatisfaction points from the customer's perspective in network development so that customers can use their mobile phones comfortably at any time.

As we move from 3G to LTE and from feature phones to smartphones, the need for network quality improvement will continue to grow.

Technological improvements have been remarkable in the last few years, the maximum speed of LTE has increased several times, and the traffic of smartphones has increased dramatically.

On the other hand, there is a limit to the band of radio waves that can be used, and communication may inevitably slow down in crowded places. In February 2015, we organized a specialized unit for improving network quality, "SQAT", so that you can use it comfortably even in such situations.

――Is the name "SQAT" a play on the Japanese word "sukatto"?

Mr. Miyao That's a retrofit (laughs). The official name is "Special Quality And Tactics". Discover improvement points using big data. We will spread the accumulated know-how nationwide and speedily improve dissatisfaction with communication quality.

――Please tell us about your specific efforts.

Mr. Miyao For example, on a train, the speed tends to slow down during the morning and evening rush hours. We are implementing intensive network measures so that data communication can be used comfortably even during such congestion.

For that purpose, information gathering is indispensable. What makes SQAT unique is that it continues to conduct surveys in the real environment. By rail, we regularly conduct data communication speed surveys during commuting hours on major commuting routes in Higashi-Meihan.

――How often do you go?

Mr. Yoshinori Miyao, General Manager, Area Quality Enhancement Office, KDDI Technology Headquarters Mr. Miyao We carry out surveys on all routes once a quarter as an overall inspection. After conducting a survey once, issues can be seen in various places. We continue to make steady improvements by addressing each of these issues between general inspections.

By the way, the total distance of the surveyed lines is about 2400km. Approximately two and a half years after the inauguration of SQAT, we have conducted quarterly inspections a total of 10 times. If you accumulate the distances investigated so far, it will be half the circumference of the earth.

――Measuring equipment is likely to be a large baggage, but how do you bring it in during rush hours?

Mr. Miyao It's a confusing story, but I'm investigating by boarding a train that arrives at the terminal station at 8:30 in the morning from the first train station. We put the equipment on our lap and measure it so that the customers around us do not feel uncomfortable.

Rather than trying to increase the speed at peak times, the purpose of these railway surveys is to prevent slowdowns and eliminate the feeling of "slow, frustrating". For that purpose, big data analysis alone is not enough, and I think it is important to firmly confirm what the customer feels is strange in the actual product.

――What kind of initiatives are you doing other than railways?

Mr. Miyao Another important initiative to improve communication dissatisfaction on the move is the expressway. Here, in addition to data communication, we are also focusing on improving the quality of voice calls, that is, VoLTE.

In voice calls, if you hang up while you are on the move, you are inconvenienced. Therefore, SQAT conducts regular driving surveys even on highways and evaluates the network. For example, on the Tokyo Metropolitan Expressway Inner Circular Route, we conduct monthly driving surveys with the goal of zero cuts.

Of course, we are also working on expressways outside the Metropolitan Expressway. Regular evaluations are conducted on major expressways nationwide, such as the Tohoku Expressway and the Kan-Etsu Expressway. Earlier, I mentioned that I investigated the distance of half the earth around the earth in the railway survey, but since the distance is longer on the highway, it will probably exceed one orbit of the earth (about 40,000 km) in about one year. I think I'm running.

――What are the causes of the call being cut off?

Mr. Miyao For example, in urban areas, when a new building is constructed, it will change the radio wave environment in the surrounding area. Also, when a new base station is set up, the communication path will naturally change, so while there will be places where the radio wave environment will improve, there may be places where it will deteriorate. Such locations can be quickly identified by field surveys and improved by tuning the base station.

――If you just build a base station without thinking about anything, there is a disadvantage that it will be cut off.

Mr. Miyao That's right. Since you are using VoLTE with high sound quality, we are continuously working on improvement to create an inseparable network.

Since 2014, au has introduced VoLTE-only machines (not compatible with 3G) to the market. For two and a half years since then, we have continued to enhance the area and tune the network.

As a result, the disconnection rate during VoLTE calls has dropped to about one-sixth that of two and a half years ago. This is the power of the au VoLTE network at the moment. Thanks to our customers' evaluation, we were able to become the number one customer satisfaction level for the second consecutive year in the JD Power survey.

――Currently, au is the only company in Japan that offers VoLTE-only networks. From the historical background, I think that au needed to proceed with the winding up of 3G as soon as possible, but is it an advantage in the future to proceed with the transition to VoLTE as soon as possible (* 3G? While NTT DoCoMo and Softbank have adopted the W-CDMA system, which has become the majority in 3G, au has adopted the CDMA2000 system, which has become the minority).

Mr. Miyao Of course, in anticipation of the coming VoLTE-only era, we have made some systematic transitions. One result is that the number of cuts has decreased in the last two years. As a “VoLTE pioneer,” we will make use of the know-how that we have been working on early to provide better services to our customers.

--The "au Wi-Fi connection tool" provided for au users is equipped with a function that automatically reports the communication status, but the data acquired from that app is also useful for improvement. Is it?

Mr. Miyao Of course. The radio wave condition is particularly bad, and it is now possible to visualize the location with the data from the app.

On the contrary, it is quite useful to know the change of the place where the improvement measures are taken after the measures are taken. What happened to not be reproduced when we went to the site for verification by ourselves may actually be that communication was slow only in a specific scene, and we identified the range that would cause inconvenience to customers earlier. Because it can be done, it can lead to speedy measures.

――Are there any severe “difficulty in improving network quality” no matter how much you take measures?

Mr. Miyao After all, mammoth stations like Shinjuku and Shibuya are tough. Although it is the place where the latest high-speed technology is introduced early, first of all, it is a battle for the location of the base station. Especially around the scrambled intersection in Shibuya, there are few buildings without base stations.

Mr. Takeshita After that, it's a stadium. This is also a place where people gather, just like the terminal station. And due to structural restrictions, there is only a limited space for the antenna.

――The efforts of "SQAT" so far have focused on improving network quality, but how about expanding the coverage area?

Mr. Miyao We are engaged in activities to expand the LTE area beyond the city. If you go to an interesting place, there is an initiative in Oze National Park.

Oze is a vast marsh surrounded by high mountains. Since the entire area is designated as a national special natural monument, it is difficult to set up a base station, and until now it has been a place where mobile phone services of any carrier cannot be used. In consultation with the Ministry of the Environment and local residents, au is building an environment where LTE can be used at the mountain lodge in Oze. As of the end of October 2017, LTE services are being provided at 19 of the 21 mountain lodges in Oze (* related article).

Mr. Yasushi Watanabe, 1G Group Leader, Area Quality Enhancement Office, KDDI Technology Headquarters Mr. Watanabe In line with this measure, we have also started to provide free Wi-Fi "OZE GREEN Wi-Fi" that anyone can use in Oze. This free Wi-Fi also has a multilingual guide display, which is also used by foreigners visiting Japan.

When I talked to people in the Oze area, there was a troubled voice saying, "I want to educate foreigners about the manners and rules of Oze, but it is difficult because I can't understand the language." In this "OZE GREEN Wi-Fi", the landing page displayed when connecting, introduces manners in multiple languages ​​even in Oze. From the perspective of CSR (Corporate Social Responsibility), I think we were able to cooperate with the local community.

――Is it possible to promote LTE areas in places such as mountainous areas where utility poles cannot be easily erected and wired?

Mr. Miyao Of course. We will listen to the voices of our customers and steadily improve the area while considering convenience.

Mr. Takeshita This spring, the Okukami Highlands of Nagano Prefecture will be made into a service area by a special method called "mountain reflection" (* related article). The area targeted for area conversion is an outback area where communication lines and power sources cannot be secured, but areas that use reflected waves by sending radio waves from the base station on the other side of the mountain and hitting the steep rock wall. I succeeded in making it.

If radio waves are reflected, they will be dissipated, so the method of mountain reflection cannot be used unless the conditions are met. I want to do it.