In this blog post, we will look at the reasons why the Wi-Fi in the Seoul subway is so slow and ways to improve it.
The number of passengers on the Seoul subway per day is about 4.18 million. Even if we do a simple calculation, about 40% of the population of Seoul takes the subway every day, so it can be said to be a truly public transportation system. The subway is not just a means of transportation, but a part of life that is closely connected to the daily lives of Seoul residents. During rush hour, we often witness the noise and speed of the subway and the tangled human crowds inside.
However, this reliable public transportation can sometimes feel frustrating. You may have experienced the frustration of trying to use the internet on the subway and having trouble connecting to Wi-Fi, so you ended up using a paid network. In fact, with the widespread use of smartphones, Wi-Fi has become an essential part of modern life. Wi-Fi is now available in coffee shops, public places, and even at home, and it has become commonplace to use the internet freely. However, Wi-Fi on subways often falls short of our expectations. Why is it that Wi-Fi on subways is so bad? There are three main reasons for this. To understand these reasons, we will first look at routers.
Using the Internet is like going back and forth between home and home. Just as you need to know the address of a house to find each other, you need a unique IP address to use the Internet. However, there are cases where the first part of the address is the same and only the last digit is different, just like the residents of an apartment building. These people use the elevator to go to their respective homes in the apartment building. Similar to the elevator, the router helps users with the same IP address to use the Internet. There are two main factors that determine the smoothness of using the Internet through a router. One is the performance of the router, which determines how many devices can be connected to the router. The other is the speed of the Internet supplied to the router, which determines the upper limit of individual speeds. Devices connected to the router share the Internet, so each speed cannot exceed these values. You can think of these factors as the size and speed of an elevator.
However, such technical explanations alone cannot explain all the problems with Wi-Fi. This is because, in addition to technology, human desires and needs are also intertwined. People want fast and stable internet connections anytime, anywhere. As expectations rise, the instability of subway Wi-Fi becomes more pronounced. We are always looking for ways to save time and be more efficient in our daily lives, and traveling on the subway is no exception. Even during this short time, people want to use the Internet, read the news, and access social media. However, if these needs are not met, people feel uncomfortable.
Sometimes it takes a long time to use the elevator in an apartment. In addition to that, we can think about the reasons why Wi-Fi is not working well in subways. First of all, no matter how large the elevator in an apartment building is, if many people use it at the same time, it will create a bottleneck. Similarly, the number of people on the subway is a problem. In the subway, there is one router installed per carriage for each telecommunications company. Theoretically, up to 250 users can connect to these routers at the same time. At the same time, it can be said that the performance is better than that of a home router that can connect about 10 people. However, since the internet is shared through the router, each Wi-Fi becomes slower as the number of users increases, eventually causing congestion for all users. When more than 300 people are in a subway car during rush hour, the Wi-Fi may become unavailable as the router’s performance is exceeded.
Even if the elevator in an apartment is slow, it will take a long time to use it. The same is true for the internet speed supplied to the Wi-Fi router in the subway. The unit of internet speed is usually measured in megabits per second (Mbps), which is the amount of information transmitted per second. Wired internet is 100 Mbps, and LTE used by smartphones is about 75 Mbps. The Wi-Fi router in the subway is connected to an internet service called WiBro. WiBro is an Internet service designed to communicate with devices moving at speeds of up to 120 km/h, making it suitable for use in subways that travel at speeds of up to 80 km/h. However, WiBro has a maximum communication speed of about 25 Mbps, which is very slow compared to LTE or wired Internet. Therefore, subway Wi-Fi is inevitably slower than Wi-Fi from routers connected to LTE or wired Internet.
However, there is one more reason that makes subway Wi-Fi even less reliable than these. It is the relationship between the characteristics of the router and the time between subway stations. The router stores the information of the devices for about two minutes so that it can be quickly restored even if the connection is inevitably lost. However, these two minutes are almost the same as the time it takes to get from one subway station to the next. In other words, the router installed in the subway remembers the information of the devices of people who have gotten off or moved to another carriage for about one more station. So, new devices recognize the router, but the router does not connect the new device to Wi-Fi. This is similar to the situation where people in an apartment building press the elevator button and the elevator stops at every floor without anyone getting on. On the other hand, even if the information stored by the router is deleted after two minutes, the connection may still not be established because new people get on at the next stop. This phenomenon becomes more serious as more people get on the subway.
To solve the problem of poor subway Wi-Fi, you need to improve the performance of the router, increase the speed of the internet provided, and adjust the device information storage time. However, the method of increasing the speed requires replacing the internet service itself, which is costly. And if you consider the stability of the Wi-Fi connection, you can’t just reduce the device information storage time. Therefore, the realistic solution is to improve the performance of the router and implement a process that can deal with meaningless device information. If there is no information exchanged between the router and the connected device, the device can be deleted after inspection.
Unfortunately, however, there is nothing that users can do to use subway Wi-Fi in Korea. The cause of these problems lies with the service provider, and the solution lies with them as well. However, Korean telecom companies are hiding the fact that the benefits of improving subway Wi-Fi are small and are offering products such as unlimited plans using the current situation as a hostage. This behavior of only pursuing profits while ignoring the inconvenience of users does not contribute to the Internet industry in the slightest. The Internet industry can only continue to develop if there are users. It is time for telecom companies to take responsible action.
