Why is my T-Mobile 5G Internet slow at night?

T-Mobile Home Internet users are deprioritized effectively below mobile phone users during congestion. If your local tower is busy at prime time (7-11 PM), your speeds will drop significantly compared to daytime.

Where is the best place to put my T-Mobile Gateway?

Place it on a high shelf near a window that faces the nearest cell tower. Avoid basements or placing it behind large appliances or TVs.

What is a good SINR value for T-Mobile 5G?

SINR (Signal-to-Interference-plus-Noise Ratio) measures signal quality. Over 20 dB is excellent. Between 10-20 dB is good. Below 0 dB means your connection will be unusable.

What is the T-Mobile Gateway Login IP?

The default IP for most Nokia, Arcadyan, and Sagemcom gateways is 192.168.12.1.

How do I login to my T-Mobile Gateway?

Connect to Wi-Fi, go to http://192.168.12.1, and enter the admin username and password found on the sticker on the bottom/back of the device.

T-Mobile Speed Test

This page helps users of T-Mobile Home Internet understand their 5G speed test results and determine whether the connection is performing within the normal range for Fixed Wireless Access (FWA).

T-Mobile Home Internet uses the same 5G cellular network as mobile phones. While download speeds can be very fast (300+ Mbps), actual performance fluctuates heavily based on signal strength (RSRP/SINR) and tower congestion.

How to interpret your T-Mobile speed test result

A T-Mobile speed test measures three core performance metrics:

Download speed – Typical ranges are 72–245 Mbps. If you are near a 5G UC (Ultra Capacity) tower, speeds can exceed 500 Mbps.

Upload speed – Important for video calls. Ranges are typically 15–31 Mbps. Weak signal often kills upload speed first.

Latency (ping) – 5G latency is higher than cable/fiber (expect 30–50ms). If it drifts over 100ms, you are jumping between bands (e.g. from n41 to n71).

These values should be evaluated based on the time of day. T-Mobile prioritizes mobile users over home internet users during congestion.

T-Mobile 5G Home: Expected Performance

Connection characteristics

Technology: 5G Fixed Wireless Access (FWA)

Deprioritization: Speeds may slow down during "heavy traffic" even if you haven't used much data.

Bands: n41 (Fastest, short range) vs n71 (Slower, long range).

Typical real-world performance

Download speed: ~100-300 Mbps in good coverage areas. ~30-50 Mbps in rural areas.

Upload speed: 10–40 Mbps.

Latency: 30–50ms (Loaded ping can spike to 200ms).

If your download speed is under 20 Mbps, you likely have poor placement or are too far from the tower.

Common Causes of Slow T-Mobile Speeds

Slow speed test results are usually caused by signal physics rather than account issues.

Frequent causes

Bad Placement: The gateway is in a closet or basement. It needs a window view.

Overheating: The "Trash Can" (Nokia) and Arcadyan gateways can overheat if placed in direct sunlight.

Tower Congestion: Occurs typically between 6 PM and 10 PM when everyone is streaming video.

T-Mobile Gateway Login – IP, User & Password

Access your 5G Gateway admin panel to check advanced signal metrics like SINR and RSRP, which are the secret to faster speeds.

T-Mobile Gateway Details	Information
Login IP Address	192.168.12.1 – Default for Nokia, Arcadyan, Sagemcom KVD21
Default Username	admin
Default Password	(Printed on the device sticker)

Steps to Login

Connect to your T-Mobile Wi-Fi
Open a browser
Enter 192.168.12.1
Enter credentials from the sticker
Navigate to "Status" > "Cellular" to see metrics

Troubleshooting Gateway Errors

Code WAN002: No 5G signal connection. Move device to a window.

Code WAN005: SIM card error. Reseat the SIM card tray.

Code WAN102: Authentication error. Reboot the gateway.

Important Signal Metrics (The Secret Sauce)

To really optimize your speed, login and check these values:

RSRP (Signal Strength): Needs to be higher than -100 dBm (e.g. -80 is great).
SINR (Signal Quality): The most important number. Needs to be positive. Above 20 dB is perfect. Below 0 dB is unusable.

When to contact T-Mobile support

You should consider contacting T-Mobile support (1-844-275-9310) if:

You have an excellent signal (RSRP > -85) but speeds are under 5 Mbps.

The display shows an error code (like WAN002) that won't clear after a reboot.

You suspect the tower is down (no service at all).

T-Mobile Speed Test FAQs

Why is my T-Mobile internet fast in the morning but slow at night? This is deprioritization. Your tower is congested, and T-Mobile prioritizes cell phone traffic over Home Internet traffic.

Can I use an external antenna? Some gateways have ports (like the new specific models), but many users modify their gateways to add 4x4 MIMO antennas. This can vastly improve SINR and speed.

What is 5G UC? 5G Ultra Capacity. It uses mid-band (n41) spectrum. It is much faster than "Extended Range" (n71) but travels shorter distances.

Competitors & Alternatives

If T-Mobile 5G Home Internet isn't working for you:

Verizon 5G Home: Similar 5G service, but uses C-Band and different towers.
Starlink Speed Test: Better for extremely rural areas with no cell signal.
Xfinity Speed Test: If cable is available, it is more stable for gaming.