[srsran-users] Unable to find the ENB 4G network using u-blox SARA-R422S-01B-00 modem

[Robert Falkenberg]

Hi,

the modem seems to only support "LTE Cat M1", "LTE Cat NB2", "2G GPRS / 
EGPRS".
I can't see it supporting plain LTE.

(Also note Cat M1 is 1.4MHz, whereas the config you posted has 
"n_prb=15" = 3MHz.)

Best regards,
Robert

On 07.02.24 18:47, sobol6803 at gmail.com wrote:
>
> Hello,
>
> My current configuration:
>
>   * EPC and ENB runs on Intel i5-9400 (all cores in performance mode),
>     Ubuntu Server 22.04.3 LTS (kernel 5.15.0-92-generic)
>   * UE's: an Android tablet and a custom device with u-blox
>     SARA-R422S-01B-00 modem (3GPP Release 13 LTE Cat M1)
>   * Ettus USRP B210 with all 4 antennas connected, external power, no
>     external clock
>   * sysmocom sysmoISIM-SJA5-9FV sim cards
>
> Everything works on the Android tablet - I can find my network and 
> connect to it. The 4G works and so does the internet.
>
> But the SARA modem cannot even find the network. It can read the 
> sysmocom sim card (CCID, preferred MCCMNC), it works with other 
> commercial sim cards (and their corresponding networks), but it just 
> will not find my custom 4G network. I have tried to modify the IMSI 
> and preferred MCCMNC of the sim card from the default 99970 to one of 
> a commercial network from another country, but it did not help (worked 
> on the tablet though).
>
> Sending "AT+COPS=?" to the modem returns only commercial networks in 
> range.
> Sending "AT+COPS=1,2,"MCCMNC",7" returns "+CME ERROR: no network 
> service" and both EPC and ENB logs do not show any connection attempts.
>
> Current configuration:
>
> # epc.conf
> [mme]
> mme_code = 0x1a
> mme_group = 0x0001
> tac = 0x0007
> mcc = 999
> mnc = 70
> mme_bind_addr = 127.0.1.100
> apn = srsapn
> dns_addr = 8.8.8.8
> encryption_algo = EEA0
> integrity_algo = EIA1
> paging_timer = 2
> request_imeisv = false
> lac = 0x0006
>
> # enb.conf
> [enb]
> enb_id = 0x19B
> mcc = 999
> mnc = 70
> mme_addr = 127.0.1.100
> gtp_bind_addr = 127.0.1.1
> s1c_bind_addr = 127.0.1.1
> s1c_bind_port = 0
> n_prb = 15
> tm = 2
> nof_ports = 2
> [rf]
> dl_earfcn = 1934
> tx_gain = 80
> rx_gain = 40
> device_name = UHD
> device_args = auto
>
> # user_db.csv (anonymized)
> sim1,mil,999701111111111,11111111111111111111111111111111,opc,11111111111111111111111111111111,9000,000000000464,9,dynamic
>
> Everything else is default.
>
> Do you know what could be the problem? Is the ENB misconfigured, or is 
> the modem somehow incompatible with my network?
>
> _______________________________________________
> srsran-users mailing list
> srsran-users at lists.srsran.com
> https://lists.srsran.com/mailman/listinfo/srsran-users

-- 


      RobertFalkenberg

Senior Engineer

Software Radio Systems

	

	
	

	

	robert at srs.io <mailto:robert at srs.io>

	www.srs.io <//www.srs.io>

	Dortmund, Germany




	
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