JTOWER's indoor Infra-Sharing solution celebrated its 10th anniversary in September 2024. In this column, I would like to share episodes from the time when we launched the services, as well as some behind-the-scenes.

Started the services when the term “Infra-Sharing” was not common

In large buildings with a floor space exceeding several hundred thousand square meters, there is a strong need to create a dedicated communication environment to ensure stable mobile phone connectivity.
By utilizing Infra-Sharing for indoor coverage, mobile network operators can not only reduce capital and operational expenses but also simplify communication with real estate owners through a single contact point. This approach reduces space and power consumption within the building, minimizes construction work, and promotes environmentally friendly and efficient network development.

In recent years, the use of Infra-Sharing for indoor coverage has become widespread, and the number of service providers is gradually increasing. However, when JTOWER was founded in 2012, the term ‘Infra-Sharing’ was not commonly used, and its adoption did not progress easily.

Developing design tools in-house to increase efficiency

JTOWER’s strength lies in its technological capabilities, which encompass everything from the development of Infra-Sharing equipment to post-installation maintenance and operation. The equipment is developed based on the quality requirements of mobile network operators, with JTOWER defining the specifications in-house and then having the equipment manufactured by vendors.

Starting the business involved discussions on specifications and connection tests, obtaining certifications, and establishing operational workflows with mobile network operators, which resulted in a lengthy timeline before the service could launch. However, because we develop the equipment in-house, we can quickly respond to questions from their technical teams and address any issues that arise.

In providing Infra-Sharing services, ensuring network quality that meets mobile network operators’ standards is crucial. JTOWER has established an operational system that MNO can trust, and through steadily building our track record, we take pride in having laid the foundation of Infra-Sharing in Japan.

We not only manage the construction during installations but also design radio coverage areas. Drawing on our knowledge of radio propagation and the expertise gained from various projects, we propose optimal equipment installations tailored to the unique characteristics of each facility.

I joined JTOWER in early 2014, during the time when the company was building the foundation for various services, including the development of original Infra-Sharing equipment and the establishment of operational systems. All of these services were initiatives that marked a first in Japan. I was responsible for developing the operation system for network coverage design.

In the beginning, we handled calculations using non-digital methods and designed the network manually. However, we later developed our own design tools, which improved our efficiency. As we gained experience designing various types of buildings, we steadily built our expertise, enabling us to propose optimal equipment installations tailored to the unique characteristics of each facility.

Challenges of network design: Arenas, stadiums, and deep basements

Since launching our first commercial service at AEON MALL TAMADAIRANOMORI (Hino City, Tokyo) in September 2014, the number of installations has gradually increased. By May 2016, 3 mobile network operators began using our services, and in March 2020, Rakuten Mobile joined, bringing the total to 4.

In October 2020, we completed the development of Japan’s first Infra-Sharing equipment compatible with the 5G Sub-6 band. Following its installation at the Tokyo Metropolitan Government in November 2020, the number of installations began to rise. By October 2020, we had achieved 200 installations, and as of the end of June 2024, that number had grown to 589, approaching 600 installations nationwide for 4G and 5G in Japan.

In terms of building categories, we initially focused on shopping centers and office buildings, but we have now expanded to a wide range of locations, including hospitals, arenas, stadiums, logistics centers, and airports.

One of the most challenging locations is deep basements. Depending on the thickness of the walls, antennas must be installed quite densely to ensure adequate coverage. While the requirement for numerous antennas can increase costs and sometimes raises concerns about being excessive, we always verify our calculations and draw on our experience to recommend the necessary number of antennas and their optimal placement.

In the past couple of years, we’ve seen a rise in installations in arenas and stadiums. This trend is not limited to new constructions; there is also an increasing demand for communication infrastructure in existing arenas and stadiums to accommodate recent technology and service, such as electronic payments, video streaming, and real-time voting. As a result, we are receiving more inquiries about the upgrades.

Network design for arenas and stadiums is quite challenging. Large venues can accommodate a significant number of people at once, requiring complex coordination for Infra-Sharing service providers. However, as our experience has grown, we have gained valuable expertise. We believe there is still plenty of room for improvement in creating comfortable communication environments.

As we move forward, we aim to continue collaborating with mobile network operators and a diverse range of partners to evolve as an Infra-Sharing provider that can adapt to the unique technologies for 5G.

※The content in the article is at the time of publication.