Today, reliable 5G is a must for homes and offices. Many use 5G routers like the Zyxel NR5103, but indoor signals can be weak. Adding a high-quality external antenna, like the Maswell Cubic 4x4 MIMO, can boost your signal, speed, and stability. This guide walks you through the setup using a TIM SIM card.

Step 1: Insert the SIM Card
Start by prepping the Zyxel NR5103. Open the rubber flap on the bottom to reach the SIM slot. Insert your nano or micro SIM (use an adapter if needed) until it clicks, then close the flap. This connects you to the cellular network.

Step 2: Perform Initial Setup and Baseline Test 

 Plug in the power and run an Ethernet cable from the router to your computer. Set the rear switch to Internal Antennas. Once the lights show a stable connection, turn off your computer's Wi-Fi and run a connection test to verity the router is online or not. Log into the admin panel (check the label for the password) to finish the setup.
 
 
Step 3: Find the Optimal Location

The best antenna location is where the signal is strongest. Use your smartphone to measure RSRP (Reference Signal Received Power). On Android, install LTE Discovery and check the RSRP value in the Discover tab. On iPhone, dial `*3001#12345#*` to enter Field Test Mode. RSRP is shown as a negative dBm value—closer to zero is stronger. For example, -76 dBm is excellent, while -115 dBm is weak. Walk through your home, checking windows, balconies, and different rooms. Pick the spot with the best signal.


Step 4: Prepare the Maswell Cubic 4x4 MIMO Antenna

Unbox the antenna, which features an omnidirectional design ideal for flexible indoor or outdoor use without precise tower alignment. The package includes four coaxial cables, a wall-mount bracket, and U-shaped clamps for pole installation. This versatile antenna captures signals from multiple directions, making it user-friendly for most environments.

Step 5: Connect the External Antenna 

Power off the router and disconnect the power supply for safety. Remove the protective covers from the four external antenna ports on the router’s back. Attach the four cables from the Maswell Cubic antenna to these ports—connection order does not matter due to the system’s flexible design. Switch the antenna selector to External Antennas, reconnect power, and allow the router to re-establish the network.


Step 6: Test Performance and Optimize Placement

Run another speed test under the same conditions to compare results. The external antenna typically delivers noticeable improvements in speed and signal quality. For best performance, mount the antenna on a wall or outdoor pole using the included hardware.

Although indoor placement is easier, outdoor installation usually offers better performance. Once we mounted the antenna outside, our results improved significantly. The 5G signal indicator jumped from two bars to five full bars. You'll be ready for 4K streaming, large file transfers, and responsive online gaming.
 

This setup process is straightforward and takes only a short time. Unlike directional antennas that require precise aiming at a cell tower, the Cubic's omnidirectional design receives signal from all horizontal directions.
 
The 4x4 MIMO technology supports multiple data streams for higher throughput,while the omnidirectional pattern ensures reliable coverage without constant adjustments.Users in areas with marginal signals will benefit most, enjoying more stable connections for streaming, video calls, and daily online activities.

In short, adding a 4x4 omnidirectional antenna to your 5G router is a great way to get more out of your service. Just remember to power off before connecting anything and try different spots to find the best signal. With these steps, you'll have faster, more reliable internet in no time.
 
Detailed Video Demonstration of Omni-directional 4x4 MIMO antenna installations (Courtesy of Saverio Cirillo) :
English:https://youtu.be/1JJR8_JZJGY?si=egyFoKEgB3HP1d85
Italian: https://youtu.be/O8Kgi9dRqnA?si=K6vHZzhwRuTCEVVu
Germany：https://youtu.be/KCJRQtTns_I
French：https://youtu.be/FTW4bsRuims
Spanish：https://youtu.be/WgLvN6Xtli8