hello everyone , i was planning on doing a LTE network using LimeSDR and srsRAN ,looking at the guide from srsRAN they are saying that i need 2 SDRs 1 for the eNB and EPC and 1 for UE .
My question is cant i do a network with only 1 SDR (Limesdr +duplexer) and for the UE just use a normal phone with a custom SIM card that i configure ,or a dongle instead of phone
here is the guide im referencing:
https://docs.srsran.com/projects/4g/en/latest/usermanuals/source/1_setup.html
Yes, you can.
See also the LibreCellular documentation:
There is an srsRAN fork with native Lime API integration, which in our testing gives better performance and stability than using it via SoapySDR.
i know this question might have been asked before but do you think VoLTE is possible with this setup
Yes and it’s on the roadmap to create a LibreCellular set of configs and how-to.
However, you could also try using the Docker configs from @herlesupreeth:
You’ll already have the eNB, so won’t need that or the UE component. Just Open5GS, IMS and IMS HSS I think.
Alright will check it out ,last thing for now ,when configuring the SIM and EPC do you know what most ppl are doing for the PLMN , are they using the test PLMN or is there a other way
thanks a lot for the response ,appreciate it
Most probably use the test PLMN. The ITU allocated 999-99 for private networks, but when I configured this I found issues with at least one UE attaching, which was resolved by reverting to 001-01. That said, more testing is required to properly confirm this, as it’s always possible this was a red herring.
I’ve got P-LTE on the test 001/01 PLMN with Docker/Kalio as and IMS System. Using cheapo off-the-shelf USIM/ISIM and SysmoCom SIM. UE are Pixel5 that I can get it to support different PLMN and Band. I can broadcast at very low power (for testing) on 3GPP Band-8 and got the UE to RACHES, ATTACH, and setup PDN to access the SGi/APN network.
For a different application testing, here in the States, per FCC ruling, there is a special Band-8, where the Center Freq UL/DL duplexing/spacing is only 39MHz instead of the standard 3GPP Band-8 at 45MHz. Chanel Bandwidth is only 1.4MHz (~15 PRBs). In the enb.conf file, I’ve tried:
[rf]
dl_earfcn = 3580
dl_freq = 938
ul_freq = 899 (This here, the LimeSDR chip can’t calibrate TX/RX)
I can set:
[rf]
dl_earfcn = 3580
#dl_freq = 938 (DL is taken by EARFCN #)
ul_freq = 899 ul_earfcn=21640 for desire 39MHz separation, but-0 in output
With QXDM view, UE can see DL and RACHES, but RRC Setup Request MSG never reaches the ENB due to no UPLINK Chanel allocated.
I’ve tried to upgrade to the latest srsLTE and LimeSuite/Driver. I don’t think the srsenb is setup to support “flexible duplexing” - non standard 45MHz duplexing.
I know that the UE needs to support this non standard duplexing, but the eNB is not even broadcasting on the UL:
Setting frequency: DL=938.0 Mhz, UL=0.0 MHz for cc_idx=0 nof_prb=25
[INFO] Tx calibration finished
[INFO] Rx calibration finished
Any pointer if SRSENB can be re-compile to support is appreciated or does librecellular support different duplexing.
Thanks
Found the issue, the enb.conf UL/DL freq is in Hz, so I had to set this for UL/DL:
[rf]
dl_earfcn = 3580
dl_freq = 938000000
ul_freq = 899000000
tx_gain = 60
rx_gain = 40
device_name = soapy
then when running, I see this:
==== eNodeB started ===
Type to view trace
Setting frequency: DL=938.0 Mhz, UL=899.0 MHz for cc_idx=0 nof_prb=6
[INFO] Tx calibration finished
[INFO] Rx calibration finished
thank you.