Before getting started, it’s always a good idea to run a couple of speed tests indoors from a device connected to your Gateway’s WiFi. The results will fluctuate a little, but this is the baseline you’re trying to improve.

Once you’ve tested your baseline internet speeds, you’re ready to install external antennas. The T-Mobile 5G Internet Gateway doesn’t have any external antenna ports, but it’s possible to access the internal ports and install adapters that allow you to connect antennas.

In the next section of this guide, we’ll show you how to open up your Gateway, connect adapters for external antennas, and close it back up.

Before you get started, you will need the following:

• A small phillips head screwdriver
• A Torx T10 screwdriver
• A small/thin flat-head screwdriver
• A thin plastic prying tool, needle-nose pliers, or tweezers
• Four U.FL to SMA-Female pigtail adapters (included in our 4×4 External Antenna kits)
• Tape for labeling cables. Painters tape works best.
• A secure container to keep screws and small parts safe while you work

Step-by-Step Guide to Installing Adapters for External Antennas

Step 1: Power off the T-Mobile 5G Internet Gateway and unplug the power cable.

Step 2: Unscrew the Phillips head screw securing the SIM card holder and remove the SIM card holder, as pointed at by the top arrow below.

Step 3: Unscrew the two T10 screws from the bottom cover.

Step 4: Use the flat head screwdriver to press between the side and bottom cover to pry away the bottom cover from the side cover. “Twist” the flat head screwdriver to further displace the bottom cover from the side cover and gently pull the bottom cover away from the casing until it releases from the internal clasps.

Step 5: Release the power cable and clip securing the battery then remove it from the device.

Step 6: Remove the four T10 screws securing the outer casing in each corner.

Step 7: Now remove the outer casing. Be careful not to damage the clips on any of the ethernet ports, and ensure the power button stays in the off position (pushed out) when sliding the casing off.

Step 8: Rotate the gateway to see a series of five black cables connected to the board by small U.Fl connectors.

• The four white-striped cables located on the U.FL ports labeled “L1”, “L2”, “L3”, and “L4” are used for cellular antennas. These cables will need to be disconnected.
• The central purple-striped cable located on the U.FL port labeled “GPS” is used by device’s the GPS antenna. This cable will remain in place.

Step 9: Use a prying tool or pair of tweezers to very carefully disconnect all four of the white-striped cables.

NOTE: Be very careful. U.Fl connectors can be quite fragile. Make sure you’re very gentle to avoid breaking the connector when disconnecting it from the board.

Once the U.Fl cables for the internal antennas are fully disconnected, coil them into the open spaces above and below the board, as shown here:

Step 10: Route your pigtail adapters through the vent port on the bottom stand (the vents are around the circumference and going inside the unit).

Tip: Routing the pigtails through the same vent port shown in the image below helps avoid obstructing the SIM card slot and any sharp bends and excessive force on the cables once re-assembled.

Step 11: Install your U.FL to N-female pigtail adapters by very carefully aligning and pressing them down into the ports you opened up in Step 9. A quiet “click” can often be heard once the connectors are pressed down and fully connected.

Tip: If you are struggling to get the pigtail connected, we recommend using a tweezers to spread the petals of the U.FL connector further apart, as shown in the image below:

Step 12 (Optional): On each pigtail adapter, tag and label its port number (1, 2, 3, or 4) by looping a piece of tape around the cable and writing down the name in pen/marker. This will help denote which adapters connects to each internal port for later referencing.

Step 13: Reassemble everything in reverse order. Make sure that your power button is in the off position before reconnecting the battery.

Congrats! Your T-Mobile 5G Internet Gateway should now be fully re-assembled, with the pigtail adapters protruding from the bottom. You are now ready to connect your external antenna(s) to the adapters you installed into your Gateway.

Step 14: Connect your external MIMO Antenna(s) to the labeled adapters installed in your Gateway using the coaxial cables included in your kit in the order shown below:

Congrats! Your T-Mobile 5G Internet Gateway is now connected to your more powerful MIMO External Antennas.

Positioning and aiming MIMO antennas well is crucial to getting the best performance to your T-Mobile 5G Internet Gateway, or indeed any other hotspot.

We’ve actually compiled a detailed UHURA instruction manual to accompany our own MIMO Antenna Kits, where we go into depth on the best ways to aim the antennas.

The goal is to find the best location and direction for the antenna(s), to maximize data rates to the T-Mobile Gateway. It can take a little patience, but can have a huge impact – it’s worth a bit of extra effort!

Connect your MIMO external antennas to your modified T-Mobile 5G Internet Gateway via the newly installed pigtail adapters, and go outside with your “test-rig”.

With each location and direction you try, run a couple speed tests, and make a note of the results. Here are all the locations and directions where we recommend testing your MIMO antenna:

Pro tip: Don’t just go to the highest point of the roof! While signal is generally stronger the higher you go, there’s also often more interference. We’ve found it’s often better to mount the antenna(s) on the side of the building where the structure can shield the antennas from interference.

Once you’ve found the position which gets you the highest data rates to the T-Mobile Gateway, that’s where you’ll want to install the MIMO antenna. Go ahead and mount the antenna, run cables inside, connect everything up, and enjoy superior data rates!

T-Mobile Gateway (Nokia 5G21) Documentation

• T-Mobile Support Page
• Quick Start Guide
• User Manual

A Helpful Guide on Installing and Maintaining U.FL connectors

• Three Quick Tips About Using U.FL