USRP B210 Setup for a First srsRAN 5G Lab

[Pavel]

Short answer: Build the lab as an attenuated conducted system: verify B210 with UHD, install a matched srsRAN and core configuration, use authorized spectrum or shielding, and start with one supported bandwidth and numerology. Proving RF and host stability comes before UE registration.

Before you start​

• Run private cellular experiments in an authorized, shielded or tightly conducted RF environment with sufficient attenuation between radio ports.
• Record RAN, core, UHD, firmware and operating-system versions together; a working configuration is a matched software and hardware set.

Step-by-step method​

1. Step 1: Run uhd_find_devices, uhd_usrp_probe and a sustained receive benchmark on the intended USB 3 controller. Record UHD and FPGA image versions.
2. Step 2: Connect TX and RX through rated fixed attenuation, splitters or duplexing needed by the lab. Calculate maximum level at every SDR and UE port; do not radiate an experimental cell openly.
3. Step 3: Configure core subscriber, PLMN, TAC, band, channel, bandwidth and sample rate consistently in the core and srsRAN. Start with project-documented example values for the exact release.
4. Step 4: Start core, then gNB, then test UE while watching synchronization, random access and registration logs. Change only the first failed layer.

Concrete example​

A B210 lab can use two separate attenuated RF paths or a carefully designed combined path, but connecting TX directly to another receiver without attenuation risks damage. Begin with low software gain and measure levels.

How to judge the result​

The baseline is complete when UHD streams without overflow, the gNB remains stable and an authorized test UE registers repeatedly with documented configuration and RF containment.

What to record​

• Troubleshoot registration in order: RF synchronization, broadcast system information, random access, RRC, authentication, security mode and PDU session.
• Monitor CPU scheduling, USB or network throughput, clock state and RAN logs during a sustained cell test.
• Use spectrum analysis and power calculation to confirm that leakage outside the controlled path remains below the lab requirement.

Common mistakes​

• Changing several hardware, software or RF variables at once, which removes the controlled comparison needed to identify the cause.
• Treating one autoscaled screenshot or one unusually good result as proof without recording the settings and repeating the test.
• Copying an srsRAN configuration from another release can introduce renamed parameters and unsupported defaults even when the hardware is identical.

Final check​

Cold-start the core, RAN, SDR and test UE in the documented order. A private-5G baseline is complete only when attach and traffic repeat inside the verified attenuated RF environment.