Setting up networks on high mountains is traditionally difficult due to brutal weather and geographic restrictions. However, KDDI and Wi2 have continuously upgraded the network for nearly a decade since 2016 during the summer seasons. In 2026, this technology has reached new heights.

For international visitors, one of the most useful services is Fujisan Wi-Fi, a free public Wi-Fi service available around mountain huts and major facilities.
Climbers can connect through their smartphone or tablet Wi-Fi settings, making it easier to check weather updates, look up route information, send photos, or contact family without relying only on international roaming.

In 2026, 5G SA service will be available at the summit and Gotemba Trail New 5th Station. Unlike standard 5G, 5G SA uses dedicated 5G equipment from the core network to the base stations, allowing for faster and more stable connections.
This is especially helpful during busy sunrise hours, when large numbers of climbers gather at the summit and use their phones at the same time. Coverage also extends to key parts of the Yoshida, Fujinomiya, and Gotemba routes, adding extra peace of mind while climbing.

Many mountain huts are located in areas where fiber-optic cables cannot be installed, making high-speed internet difficult to provide. To solve this, au Starlink Mountain Hut Wi-Fi uses satellite internet to support connectivity in these remote locations. In 2026, the service will be rolled out at 29 mountain huts, making it easier for climbers to message family, check weather conditions, and prepare for the next stage of their climb.

Here’s how the upgraded network can support a typical 2-day Mt. Fuji climb with an overnight stay at a mountain hut.

Arrive at the 5th Station before noon, such as Fuji Subaru Line 5th Station on the Yoshida Trail or Gotemba Trail New 5th Station. Take about an hour to adjust to the altitude, then connect to Fujisan Wi-Fi to check the weather, contact family and friends, and make any final preparations before heading up the mountain.
Begin hiking at a steady pace and aim to reach your reserved 7th or 8th Station mountain hut by evening. After dinner, use the available mountain hut Wi-Fi to message family and friends, check the sunrise time, review the next day’s conditions, and get some rest before the early summit push.

Before dawn, continue toward the summit with your headlamp. If the weather is clear, you’ll arrive in time to watch the sunrise as the sky brightens above the clouds.
With 5G SA coverage available at the summit, climbers can more easily share photos, contact family, or check real-time information even during busy sunrise hours. Just remember to use your phone safely, avoid blocking the trail, and take time to enjoy the view with your own eyes, too.

Don’t Use Your Phone While Walking
Mt. Fuji’s trails can be steep, rocky, and crowded. Looking at your screen while walking increases the risk of tripping, slipping, or bumping into other climbers. Always stop in a safe, wide area before using your phone.Expect Some Weak Signal Areas Even with improved coverage, some areas may still have limited signal due to terrain, especially around the Ohachi-meguri crater rim route at the summit. If you need to make an emergency call or check important information, move carefully to an open area with better reception.Be Considerate in Mountain HutsMountain huts are shared spaces where many climbers rest before the early morning ascent. Use headphones, keep your volume low, and avoid phone calls late at night or early in the morning.

For the 2026 climbing season, Mt. Fuji offers better connectivity than ever thanks to Fujisan Wi-Fi, au Starlink Mountain Hut Wi-Fi, and expanded 5G SA coverage in key areas. Together, these services make it easier for climbers to access information, stay in touch with family and friends, and enjoy greater peace of mind during their journey.
Of course, technology is only one part of the Mt. Fuji experience. From watching the sunrise above the clouds to exploring the Fuji Five Lakes and other nearby attractions, the mountain continues to offer unforgettable experiences both on and off the trail.
With proper preparation and a respect for mountain safety, you'll be ready to enjoy one of Japan's most iconic experiences.

(Source/Main Image :Wi2)