UE discovers eNB but cannot attach: Carrier Aggregation in LTE with srsRAN 4G

[rolandmartinson7890]

Hello Everyone,

I would like to know if anyone has tried out Carrier Aggregation and get it to work successfully. I am not sure if it still works with this latest version of srsRAN 4G. I followed the documentation and have the recommended x310 as both UE and eNB but can not get the UE to transmit.

I have attached the config files and here are the logs from both:

### eNB Side:

==== eNodeB started ===
Type to view trace
Setting frequency: DL=2630.0 Mhz, UL=2510.0 MHz for cc_idx=0 nof_prb=50
Setting frequency: DL=2650.0 Mhz, UL=2530.0 MHz for cc_idx=1 nof_prb=50
t
Enter t to stop trace.
RF status: O=0, U=1, L=0
t
Enter t to restart trace.
t
Enter t to stop trace.
RACH:  tti=3861, cc=0, pci=1, preamble=17, offset=23, temp_crnti=0x46
RACH:  tti=3861, cc=0, pci=1, preamble=26, offset=27, temp_crnti=0x47
RACH:  tti=3861, cc=0, pci=1, preamble=30, offset=5, temp_crnti=0x48
SCHED: Could not transmit RAR within the window (RA=3861, Window=[3864, 3874), RAR=3876
RACH:  tti=3881, cc=0, pci=1, preamble=1, offset=23, temp_crnti=0x49
RACH:  tti=3881, cc=0, pci=1, preamble=10, offset=27, temp_crnti=0x4a
RACH:  tti=3881, cc=0, pci=1, preamble=14, offset=5, temp_crnti=0x4b
RACH:  tti=3901, cc=0, pci=1, preamble=35, offset=45, temp_crnti=0x4c
RACH:  tti=3901, cc=0, pci=1, preamble=39, offset=23, temp_crnti=0x4d
RACH:  tti=3901, cc=0, pci=1, preamble=48, offset=27, temp_crnti=0x4e
RACH:  tti=3921, cc=0, pci=1, preamble=18, offset=23, temp_crnti=0x4f
RACH:  tti=3921, cc=0, pci=1, preamble=27, offset=27, temp_crnti=0x50
RACH:  tti=3921, cc=0, pci=1, preamble=31, offset=5, temp_crnti=0x51
Disconnecting rnti=0x47.
Disconnecting rnti=0x46.
RACH:  tti=3941, cc=0, pci=1, preamble=16, offset=23, temp_crnti=0x52
RACH:  tti=3941, cc=0, pci=1, preamble=25, offset=27, temp_crnti=0x53
RACH:  tti=3941, cc=0, pci=1, preamble=29, offset=5, temp_crnti=0x54
Disconnecting rnti=0x48.
Disconnecting rnti=0x4b.
Disconnecting rnti=0x4a.
Disconnecting rnti=0x49.

### UE Side:
Attaching UE...
.
Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=-0.1 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=21, tti=3861, ra-rnti=0x2
Random Access Transmission: seq=5, tti=3881, ra-rnti=0x2
Random Access Transmission: seq=43, tti=3901, ra-rnti=0x2
Random Access Transmission: seq=22, tti=3921, ra-rnti=0x2
Random Access Transmission: seq=20, tti=3941, ra-rnti=0x2
Random Access Transmission: seq=28, tti=3961, ra-rnti=0x2
Random Access Transmission: seq=25, tti=3981, ra-rnti=0x2
Random Access Transmission: seq=39, tti=4001, ra-rnti=0x2
Random Access Transmission: seq=31, tti=4021, ra-rnti=0x2
Random Access Transmission: seq=20, tti=4041, ra-rnti=0x2
RF status: O=1, U=0, L=0
Attach failed (attempt 1/5)
.
Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=0.0 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=37, tti=8981, ra-rnti=0x2
Random Access Transmission: seq=0, tti=9001, ra-rnti=0x2
Random Access Transmission: seq=42, tti=9021, ra-rnti=0x2
Random Access Transmission: seq=51, tti=9041, ra-rnti=0x2
Random Access Transmission: seq=18, tti=9061, ra-rnti=0x2
Random Access Transmission: seq=20, tti=9081, ra-rnti=0x2
Random Access Transmission: seq=1, tti=9101, ra-rnti=0x2
Random Access Transmission: seq=6, tti=9121, ra-rnti=0x2
Random Access Transmission: seq=6, tti=9141, ra-rnti=0x2
Random Access Transmission: seq=27, tti=9161, ra-rnti=0x2
Attach failed (attempt 2/5)
.
Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=-0.1 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=9, tti=3701, ra-rnti=0x2
Random Access Transmission: seq=31, tti=3721, ra-rnti=0x2
Random Access Transmission: seq=21, tti=3741, ra-rnti=0x2
Random Access Transmission: seq=1, tti=3761, ra-rnti=0x2
Random Access Transmission: seq=45, tti=3781, ra-rnti=0x2
Random Access Transmission: seq=30, tti=3801, ra-rnti=0x2
Random Access Transmission: seq=42, tti=3821, ra-rnti=0x2
Random Access Transmission: seq=30, tti=3841, ra-rnti=0x2
Random Access Transmission: seq=20, tti=3861, ra-rnti=0x2
Random Access Transmission: seq=48, tti=3881, ra-rnti=0x2
Attach failed (attempt 3/5)
.
Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=-0.5 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=17, tti=8821, ra-rnti=0x2
Random Access Transmission: seq=18, tti=8841, ra-rnti=0x2
Random Access Transmission: seq=29, tti=8861, ra-rnti=0x2
Random Access Transmission: seq=9, tti=8881, ra-rnti=0x2
Random Access Transmission: seq=40, tti=8901, ra-rnti=0x2
Random Access Transmission: seq=25, tti=8921, ra-rnti=0x2
Random Access Transmission: seq=13, tti=8941, ra-rnti=0x2
Random Access Transmission: seq=41, tti=8961, ra-rnti=0x2
Random Access Transmission: seq=12, tti=8981, ra-rnti=0x2
Random Access Transmission: seq=45, tti=9001, ra-rnti=0x2
Attach failed (attempt 4/5)
..
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Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=-0.4 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=10, tti=5461, ra-rnti=0x2
Random Access Transmission: seq=26, tti=5481, ra-rnti=0x2
Random Access Transmission: seq=21, tti=5501, ra-rnti=0x2
Random Access Transmission: seq=0, tti=5521, ra-rnti=0x2
Random Access Transmission: seq=1, tti=5541, ra-rnti=0x2
Random Access Transmission: seq=40, tti=5561, ra-rnti=0x2
Random Access Transmission: seq=49, tti=5581, ra-rnti=0x2
Random Access Transmission: seq=2, tti=5601, ra-rnti=0x2
Random Access Transmission: seq=22, tti=5621, ra-rnti=0x2
Random Access Transmission: seq=3, tti=5641, ra-rnti=0x2
Attach failed (attempt 5/5)

Core Side:
HSS Initialized.
MME S11 Initialized
MME GTP-C Initialized
MME Initialized. MCC: 0xf001, MNC: 0xff01
SPGW GTP-U Initialized.
SPGW S11 Initialized.
SP-GW Initialized.
^TReceived S1 Setup Request.
S1 Setup Request - eNB Name: srsenb01, eNB id: 0x19b
S1 Setup Request - MCC:001, MNC:01
S1 Setup Request - TAC 7, B-PLMN 0xf110
S1 Setup Request - Paging DRX v128
Sending S1 Setup Response
Received S1 Setup Request.
S1 Setup Request - eNB Name: srsenb01, eNB id: 0x19b
S1 Setup Request - MCC:001, MNC:01
S1 Setup Request - TAC 7, B-PLMN 0xf110
S1 Setup Request - Paging DRX v128
Sending S1 Setup Response
Received S1 Setup Request.
S1 Setup Request - eNB Name: srsenb01, eNB id: 0x19b
S1 Setup Request - MCC:001, MNC:01
S1 Setup Request - TAC 7, B-PLMN 0xf110
S1 Setup Request - Paging DRX v128
Sending S1 Setup Response
Received S1 Setup Request.
S1 Setup Request - eNB Name: srsenb01, eNB id: 0x19b
S1 Setup Request - MCC:001, MNC:01
S1 Setup Request - TAC 7, B-PLMN 0xf110
S1 Setup Request - Paging DRX v128
Sending S1 Setup Response
Received S1 Setup Request.

CA-4G.zip
ue.zip

[rolandmartinson7890]

@andrepuschmann

I have figured the first issue was due to the clock. The eNB was not able to transmit the Random Access Response within the expected window. I went on to connect the USRP x310's to use the same external clock and updated the config files to use the external clock. I however, am facing this problem now from the UE side.

I am getting this error: /home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4

I am running Ubuntu 22.04 on both computers and UHD_4.5.0.0. I am also using the latest srsRAN 4G software.

### eNB Screen
==== eNodeB started ===
Type to view trace
Setting frequency: DL=2630.0 Mhz, UL=2510.0 MHz for cc_idx=0 nof_prb=50
Setting frequency: DL=2650.0 Mhz, UL=2530.0 MHz for cc_idx=1 nof_prb=50
t
Enter t to stop trace.
RACH:  tti=5941, cc=0, pci=1, preamble=26, offset=1, temp_crnti=0x46

               -----------------DL----------------|-------------------------UL-------------------------
rat  pci rnti  cqi  ri  mcs  brate   ok  nok  (%) | pusch  pucch  phr  mcs  brate   ok  nok  (%)    bsr
lte    1   46    1   0    1    360    1    3  75% |  34.6   19.3    0    0     79    1    0   0%    0.0
lte    1   46  n/a   0    0      0    0    3 100% |   0.1   26.1    0    0      0    0    4 100%    0.0
Disconnecting rnti=0x46.
RACH:  tti=8141, cc=0, pci=1, preamble=47, offset=1, temp_crnti=0x47
RACH:  tti=8191, cc=0, pci=1, preamble=34, offset=1, temp_crnti=0x48
Disconnecting rnti=0x47.
RACH:  tti=8241, cc=0, pci=1, preamble=5, offset=16, temp_crnti=0x49
RACH:  tti=8241, cc=0, pci=1, preamble=10, offset=1, temp_crnti=0x4a
RACH:  tti=8241, cc=0, pci=1, preamble=16, offset=34, temp_crnti=0x4b
Disconnecting rnti=0x48.
RACH:  tti=8291, cc=0, pci=1, preamble=26, offset=1, temp_crnti=0x4c
Disconnecting rnti=0x4b.
Disconnecting rnti=0x4a.
Disconnecting rnti=0x49.
RACH:  tti=8371, cc=0, pci=1, preamble=49, offset=1, temp_crnti=0x4d
Disconnecting rnti=0x4c.
RACH:  tti=8421, cc=0, pci=1, preamble=40, offset=1, temp_crnti=0x4e
Disconnecting rnti=0x4d.
Disconnecting rnti=0x4e.
RACH:  tti=8501, cc=0, pci=1, preamble=12, offset=1, temp_crnti=0x4f
Disconnecting rnti=0x4f.
RACH:  tti=8581, cc=0, pci=1, preamble=13, offset=1, temp_crnti=0x50
lte    1   50  n/a   0    0      0    0    0   0% |   4.4    n/a   31    0    789    1    7  87%    0.0
Disconnecting rnti=0x50.

### UE Screen:

Waiting PHY to initialize ... done!
Attaching UE...
RF status: O=1, U=0, L=0
.
Found Cell:  Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=0.1 KHz
Found PLMN:  Id=00101, TAC=7
Random Access Transmission: seq=1, tti=7541, ra-rnti=0x2
Random Access Transmission: seq=49, tti=7591, ra-rnti=0x2
RRC Connected
Random Access Complete.     c-rnti=0x47, ta=1
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
Network attach successful. IP: 172.16.0.2
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
SCELL Activation / Deactivation CMD: 2
Software Radio Systems RAN (srsRAN) 23/10/2024 14:52:7 TZ:0
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
RF status: O=0, U=6, L=0
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4
/home/rocarrieraggregation-ue/srsRAN_4G/lib/src/phy/rf/rf_uhd_imp.cc:315: UHD unhandled event code 4