I have already looked at the srsRAN users mailing list and noted that another user is also facing the similar issue as mine. I am using Build 22.10 of srsRAN 4G. I am having trouble maintaining a stable attach with the UE. Knowing that my RF front-end might have unstable internal clock and as noted here, i have supplied a very stable 10 MHz external frequency reference to it, and i have verified that the front end is able to lock on to this external frequency reference.
I have collected logs and packet capture which i am attaching with this post for your further expert assessment and evaluation. The attached logs show multiple times this attach attempt is made.
[Describe the issue in detail]
Setup Details
OS: Ubuntu 22.04
Hardware: Intel® Xeon(R) CPU E5-1607 v3 @ 3.10GHz × 4 with 36.0 GiB of Memory
RF Front End: LimeSDR USB connected over USB 3.0 to the computer hardware above.
srsRAN Version: 22.10
Driver: Soapy SDR driver. Version: I can find this out if need be.
Expected Behavior
Connection to remain stable after attach.
Actual Behaviour
srsenb and UE have an unstable connection, restart attach procedure.
Build srsRAN 22.10 with Soapy Driver so that LimeSDR USB can work
Make sure LimeSDR USB driver is installed
Make necessary edits to your your ue.conf file for authentication details
Start srsepc
Start srsenb
Additional Information
Attaching the logs , config files and mac_pcap with this email. Let me know if you need any other info. Note that this issue doesn't manifest with earlier build of srsRAN such as 22.04.1 with the same RF front end(Lime SDR USB) with or without external clock reference.
To diagnose these kind of issues, better to attach logs in info mode. Other than that, I can see there are many retx at RLC level, which indicates a bad signal quality. You need to try to improve that.
Issue Description
HI srsRAN development team,
I have already looked at the srsRAN users mailing list and noted that another user is also facing the similar issue as mine. I am using Build 22.10 of srsRAN 4G. I am having trouble maintaining a stable attach with the UE. Knowing that my RF front-end might have unstable internal clock and as noted here, i have supplied a very stable 10 MHz external frequency reference to it, and i have verified that the front end is able to lock on to this external frequency reference.
I have collected logs and packet capture which i am attaching with this post for your further expert assessment and evaluation. The attached logs show multiple times this attach attempt is made.
[Describe the issue in detail]
Setup Details
OS: Ubuntu 22.04 Hardware: Intel® Xeon(R) CPU E5-1607 v3 @ 3.10GHz × 4 with 36.0 GiB of Memory RF Front End: LimeSDR USB connected over USB 3.0 to the computer hardware above. srsRAN Version: 22.10 Driver: Soapy SDR driver. Version: I can find this out if need be.
Expected Behavior
Connection to remain stable after attach.
Actual Behaviour
srsenb and UE have an unstable connection, restart attach procedure.
==== eNodeB started === Type to view trace
Setting frequency: DL=2680.0 Mhz, UL=2560.0 MHz for cc_idx=0 nof_prb=50
RACH: tti=8601, cc=0, pci=1, preamble=37, offset=12, temp_crnti=0x46
RACH: tti=9991, cc=0, pci=1, preamble=11, offset=12, temp_crnti=0x47
Disconnecting rnti=0x47.
RACH: tti=10101, cc=0, pci=1, preamble=12, offset=12, temp_crnti=0x48
Disconnecting rnti=0x48.
RACH: tti=10221, cc=0, pci=1, preamble=1, offset=12, temp_crnti=0x49
Disconnecting rnti=0x49.
RACH: tti=101, cc=0, pci=1, preamble=43, offset=12, temp_crnti=0x4a
Disconnecting rnti=0x4a.
RACH: tti=221, cc=0, pci=1, preamble=22, offset=12, temp_crnti=0x4b
Disconnecting rnti=0x4b.
RACH: tti=341, cc=0, pci=1, preamble=6, offset=12, temp_crnti=0x4c
Disconnecting rnti=0x4c.
RACH: tti=461, cc=0, pci=1, preamble=19, offset=12, temp_crnti=0x4d
Disconnecting rnti=0x4d.
User 0x46 connected
RACH: tti=2931, cc=0, pci=1, preamble=16, offset=12, temp_crnti=0x4e
Disconnecting rnti=0x4e.
RACH: tti=3021, cc=0, pci=1, preamble=43, offset=12, temp_crnti=0x4f
Disconnecting rnti=0x4f.
RACH: tti=3111, cc=0, pci=1, preamble=27, offset=12, temp_crnti=0x50
Disconnecting rnti=0x50.
RACH: tti=3201, cc=0, pci=1, preamble=17, offset=12, temp_crnti=0x51
Disconnecting rnti=0x51.
RACH: tti=3291, cc=0, pci=1, preamble=38, offset=12, temp_crnti=0x52
Disconnecting rnti=0x52.
RACH: tti=3381, cc=0, pci=1, preamble=12, offset=12, temp_crnti=0x53
Disconnecting rnti=0x53.
RACH: tti=3471, cc=0, pci=1, preamble=37, offset=12, temp_crnti=0x54
Disconnecting rnti=0x54.
RACH: tti=4261, cc=0, pci=1, preamble=27, offset=12, temp_crnti=0x55
Disconnecting rnti=0x46.
RACH: tti=5791, cc=0, pci=1, preamble=14, offset=12, temp_crnti=0x56
Disconnecting rnti=0x56.
User 0x55 connected
RACH: tti=5931, cc=0, pci=1, preamble=30, offset=12, temp_crnti=0x57
Disconnecting rnti=0x57.
RACH: tti=7311, cc=0, pci=1, preamble=22, offset=12, temp_crnti=0x58
Disconnecting rnti=0x58.
User 0x55 connected
RACH: tti=7451, cc=0, pci=1, preamble=20, offset=12, temp_crnti=0x59
Disconnecting rnti=0x59.
RACH: tti=7551, cc=0, pci=1, preamble=41, offset=12, temp_crnti=0x5a
Disconnecting rnti=0x5a.
RACH: tti=8211, cc=0, pci=1, preamble=21, offset=12, temp_crnti=0x5b
Disconnecting rnti=0x5b.
RACH: tti=8391, cc=0, pci=1, preamble=13, offset=12, temp_crnti=0x5c
Disconnecting rnti=0x55.
RACH: tti=10191, cc=0, pci=1, preamble=36, offset=12, temp_crnti=0x5d
Disconnecting rnti=0x5d.
User 0x5c connected
Steps to reproduce the problem
Additional Information
Attaching the logs , config files and mac_pcap with this email. Let me know if you need any other info. Note that this issue doesn't manifest with earlier build of srsRAN such as 22.04.1 with the same RF front end(Lime SDR USB) with or without external clock reference.
Logs_Configs_PCAP.zip