srsRAN_4G network is not detected by commodity mobile phones

Issue Description

I have setup srsRAN_4G network with B200 front end according to instructions here COTS UE. The enb starts up and connects to the epc correctly. I have used the PCS1900 band. I verified on a second SDR that there are continuous transmissions matching the expected bandwidth on the correct DL frequency, which makes me think it is working correctly.

Setup Details

Ubuntu 22.04.3 LTS (system ram 32G) UHD 4.1.0.5-3 srsRAN_4G release 23_04

Expected Behavior

The network should show up as MCC+MNC when doing cell network search with a COTS phone.

Actual Behaviour

I try to search for this network on a Pixel 7 phone fitted with a Sysmocom SIM card, but am unable to find the network when searching for it. I also tried searching for the network on a separate Pixel 6 phone with a Tmobile SIM, but can't see the network at all. I tried changing the mcc mnc to private network 999, 70 and also to 310,01 but to no avail. I also tried reducing the n_prb down to 25 even but nothing yet.

Steps to reproduce the problem

epc_config.txt enb_config.txt

Additional Information

enb output

Active RF plugins: libsrsran_rf_uhd.so libsrsran_rf_blade.so
Inactive RF plugins: 
---  Software Radio Systems LTE eNodeB  ---

Couldn't open , trying /root/.config/srsran/enb.conf
Reading configuration file /root/.config/srsran/enb.conf...
Couldn't open sib.conf, trying /root/.config/srsran/sib.conf
Couldn't open rr.conf, trying /root/.config/srsran/rr.conf
Couldn't open rb.conf, trying /root/.config/srsran/rb.conf
WARNING: cpu0 scaling governor is not set to performance mode. Realtime processing could be compromised. Consider setting it to performance mode before running the application.

Built in Release mode using commit 921f17484 on branch HEAD.

/home/nb@ABC.LOCAL/Projects/srsRAN_4G/srsenb/src/enb_cfg_parser.cc:1881: Force DL EARFCN for cell PCI=1 to 700
Opening 1 channels in RF device=UHD with args=default
Supported RF device list: UHD bladeRF file
[INFO] [UHD] linux; GNU C++ version 11.2.0; Boost_107400; UHD_4.1.0.5-3
[INFO] [LOGGING] Fastpath logging disabled at runtime.
Opening USRP channels=1, args: type=b200,master_clock_rate=23.04e6
[INFO] [UHD RF] RF UHD Generic instance constructed
[INFO] [B200] Detected Device: B200
[INFO] [B200] Operating over USB 3.
[INFO] [B200] Initialize CODEC control...
[INFO] [B200] Initialize Radio control...
[INFO] [B200] Performing register loopback test... 
[INFO] [B200] Register loopback test passed
[INFO] [B200] Asking for clock rate 23.040000 MHz... 
[INFO] [B200] Actually got clock rate 23.040000 MHz.

==== eNodeB started ===
Type <t> to view trace
Setting manual TX/RX offset to 100 samples
Setting frequency: DL=1940.0 Mhz, UL=1860.0 MHz for cc_idx=0 nof_prb=50
Starting plot for worker_id=0
Creating plot window 'srsENB PCI 1'...
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
t
Enter t to stop trace.
RF status: O=0, U=1, L=1
RF status: O=0, U=1, L=0

epc output

Built in Release mode using commit 921f17484 on branch HEAD.

---  Software Radio Systems EPC  ---

Couldn't open , trying /root/.config/srsran/epc.conf
Reading configuration file /root/.config/srsran/epc.conf...
HSS Initialized.
MME S11 Initialized
MME GTP-C Initialized
MME Initialized. MCC: 0xf310, MNC: 0xff01
SPGW GTP-U Initialized.
SPGW S11 Initialized.
SP-GW Initialized.
Received S1 Setup Request.
S1 Setup Request - eNB Name: srsenb01, eNB id: 0x19b
S1 Setup Request - MCC:310, MNC:01
S1 Setup Request - TAC 7, B-PLMN 0x13f010
S1 Setup Request - Paging DRX v128
Sending S1 Setup Response

srsran / srsRAN_4G