Recommendation for SDR hardware

[brainrecursion]

Looking to buy a new SDR for use with srsRAN, running both 5g and 4g networks for research. Probably only one or two clients at a time but ideally want something reliable.
I can see a lot of people using the Ettus B210, is this the recommended SDR for this purpose? Are there any limitations or issues with this device? I might be able to stretch to a X310 if it offered any substantial benefits. Thanks for your help.

[pgawlowicz]

Hi, this presentation contains a good comparison of the USRP devices.

Main points regarding the operation with srsRAN projects:

B210:

• It is recommended to buy an external clock which is much more accurate than the onboard clock (e.g., Leo Bodnar GPS clock)
• Max RF Bandwidth: 56MHz (or 30.72 MHz in 2x2) --> up to 40 MHz (test required) cell bandwidth, but we only tested with 20MHz
• Number of cells:
  • srsRAN-5G: 1 cell (B210 has 2 channels but 1 UHD streamer)
  • srsRAN-4G: 2 cells (with the same carrier frequency)
• 5G HO should be possible (test required) in disaggregated gNB deployment with two DU instances each connected to own B210 (need to sync the USRPs, especially in TDD scenario)

X310:

• The internal clock should be sufficient, no need to buy an external one.
• Max RF Bandwidth: 160 MHz -> up to 100MHz cell bandwidth
• Number of cells:
  • srsRAN-5G: Up to 2 cells (with different carrier frequencies) or 1 cell with 2x2 MIMO (UL MIMO available in the Enterprise version)
  • srsRAN-4G: Up to 2 cells (with different carrier frequencies)
• 5G HO possible in dis-/aggregated deployments options.

RU:

• Alternatively, you might be interested in using a commercial RU. In this tutorial, we describe all HW components required to build e2e O-RAN Testbed with srsRAN and Benetel RAN550 RU

[brainrecursion]

Thanks that is really useful to know. I don't think we will need to do handover between 4G and 5G, probably just run them independently.

I am interested that you suggested a Leo Bodnar external clock source as this is far cheaper than the board mounted one Ettus recommend. https://www.ettus.com/all-products/gpsdo-tcxo-module/
Is there any disadvantages using this instead of the Ettus one?

[pgawlowicz]

With the internal B210 GPSDO, you will get clock and time synchronization.
With Leo Bodnar, only clock synchronization. (It should be possible to implement time synchronization, but it is not available out of the box).