Operating system name and version: Centos
Version of smsd: 3.1.15
Smsd installed from: sources
Name and model of a modem / phone: Bus 001 Device 005: ID 12d1:1001 Huawei Technologies Co., Ltd. E169/E620/E800 HSDPA Modem

Interface: USB

Hello! After performing about 2-3 hours flawlessly the modem fails to the state "modem is not registered" and stays in that state until it is reinserted in a usb port again.

My config file is:
devices = E620
logfile = /var/log/smsd.log
loglevel = 8

init = AT+CPMS="ME","ME","ME"
baudrate = 38400
rtscts = no
signal_quality_ber_ignore = yes
memory_start = 0
device = /dev/gsmmodem
incoming = yes
rtscts = no
send_delay = 10
keep_open = yes

regular_run_cmd = atz
regular_run_interval = 120
regular_run_logfile = /var/log/smsd_regular_run.log
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Log file is: