Docomo Speed Test
This diagnostic utility validates the performance of your NTT Docomo internet connection. Docomo primarily provides home internet via two distinct infrastructures: Docomo Hikari (Fiber-to-the-Home using the NTT GE-PON network) and home 5G (Fixed Wireless Access using the mobile network). Your speed test results will fundamentally differ depending on which service you utilize.
Understanding Your Speed Metrics
When analyzing your connection quality, focus on these three performance vectors:
Download Speed: On "home 5G" plans, speeds fluctuate heavily based on distance from the 5G Sub-6 or mmWave base station. On "Docomo Hikari 1G" plans, speeds should remain stable. If Fiber speeds drop drastically at night, it indicates network congestion at the provider termination point (NTE).
Upload Speed: Docomo Hikari Fiber offers Symmetrical Speeds (Upload = Download), essential for sending large files. However, "home 5G" plans have significantly lower upload speeds (typically 10-50 Mbps) due to the nature of cellular networks.
Latency (Ping): For gaming, Docomo Hikari is superior, typically offering 5-15ms ping to Tokyo/Osaka servers. "home 5G" latency is higher (30-60ms) and may jitter, making it less ideal for competitive FPS gaming.
What Results Should You Expect?
The "IPoE" Factor (Crucial)
In Japan, the connection method dictates your speed. Benchmarks include:
Docomo Hikari (IPoE/v6 Plus): ~600-900 Mbps (Stable 24/7)
Docomo Hikari (PPPoE): ~200 Mbps (Day) / ~10 Mbps (Night)
home 5G HR01/HR02: ~100-400 Mbps (Highly variable)
If your Fiber speed test shows extremely low results (under 10 Mbps) specifically during the evening, your router is likely not using IPv6 IPoE. This is a configuration issue, not a broken line.
Why Is Your Docomo Connection Slow?
Before contacting the Information Center, verify these common configuration faults:
The "home 5G" Placement: The HR01/HR02 router is highly sensitive to position. It must be placed on a window sill facing the nearest tower. Placing it on the floor or in a shelf can reduce speeds by 50%.
LAN Cable Category: For "Docomo Hikari 10G" plans, you must use Cat6A cables. Standard Cat5e or Cat6 cables will cap your speed at 1 Gbps, wasting the 10G potential.
2.4GHz Congestion: In Japanese apartment complexes (Mansion type), the 2.4GHz band is saturated. Always force your device to connect to the 5GHz SSID for accurate testing.
Docomo Technical Details
| Parameter | Details |
| Router Models | home 5G HR02 / HR01 (Sharp) / Docomo 10G Router |
| Gateway IP | 192.168.128.1 (home 5G) or 192.168.1.1 (Hikari) |
| Connection Type | IPoE (v6 Plus / OCN Virtual Connect) |
| Status Lamps | 5G/4G (Blue = Good, Yellow = Weak, Red = Error) |
| Support Number | 151 (Docomo Mobile) / 0120-800-000 |
How to Get an Accurate Test
Wi-Fi performance in Japan is often limited by the dense construction materials of buildings.
To verify the actual line speed, connect a LAN cable directly from the ONU (Optical Network Unit) or home 5G router to a PC. This bypasses wireless interference. If the wired test is fast but Wi-Fi is slow, consider upgrading to a Wi-Fi 6 mesh system.
When to Call Support
Escalate the issue to Docomo if you observe these specific failures:
Red STATUS Lamp: On the home 5G router, a solid Red "STATUS" lamp indicates a SIM card error or hardware failure.
Alarm Lamp: On the ONU (Fiber modem), a Red "Alarm" or "Fail" light means the fiber optic cable is broken.
Slow Speeds (24/7): If wired speeds are consistently below 50 Mbps regardless of the time of day.
You can check network status via the My Docomo App or by dialing 151 from your Docomo mobile phone.