new B205 mini not behaving

[Jim_Ogilvie]

Dear all, I am very new to this forum so please forgive any etiquette errors.

We have been building a POC device that utilises an Ettus B205 mini i and SRS RAN. We recently purchased another B205mini i and it successfully pulled down the latest updates - or so we think.

Attached is an image of old and new with the result of uhd_usrp_probe. Newer on the left (SN 34170C7) and older on the right. Revision, FW and FPGA image are all the same.

When we run SRSRAN on the OLDer one we get a test network as expected.
When we run the newer one with exactly the same SRSRAN config (on the same machine), it appears to work but does not generate a test network. Any ideas?????

For reference we have confirmed that a GNU radio simple TX / RX test works as expected on both old and new. An independent device confirms that there is a signal being passed from TX to RX on both.

This has left us very confused with no clue where to go now, has anyone seen this issue before and have any ideas as to what is wrong?

Thank you all in advance for taking the time to read this.

[Leonard_Gartner]

Hi Jim,

could you clarify, what is the test network your are trying to generate? And what do you expect to happen versus what does actually happen?

How many b205 mini's are involved?

Maybe you can also look into the github issues for USRP related issues:
Issues · srsran/srsRAN_4G

Best regards,

Leonard

[Jim_Ogilvie]

Thank you Leonard.

The test network is an LTE telecoms network utilising srsRAN software.

The computer runs the EPC and ENB with the b205 mini i acting as the Radio Head. Once running a UE / Handset can see a "test PLMN" to potentially connect to. Depending on teh UE / OS it can present as 10101 or similar.

With the Older B205 mini i - attached as the radio head all works as anticipated. With the newer B205 mini-i attached to the same computer, running the same SW, it appears to run but no test network is visable on the UE or other UE.

Both are running the same Revision, FW and FPGA images, we have reset the newer one and we have tried to run the test on another complete set-up to eliminate any computer based issue - again newer not operating despite computer SW suggesting it is running.

Thank you, we are looking at srsRAN as well.

Jim

[Leonard_Gartner]

Hi Jim,

So far I have not found anything specific. Due to the fact that you do not even see the network, it should be related to physical layer aspects of the USRP radio head, right?

Assuming you dont synchronize the LOs, maybe the LO from the new USRP is just not good enough:
GPSDO for base station case · Issue #1175 · srsran/srsRAN_4G

Best regards,

Leonard