sorry for the inconvenience.
i find the error.
on nano /etc/config/network
my option device is not '/dev/ttyUSB0'
i find it when i do
root@OpenWrt:~# gcom -d /dev/ttyUSB0
***SIM ERROR***
Check device port configuration.
Check SIM is inserted
Test SIM in a mobile phone?
root@OpenWrt:~# gcom -d /dev/ttyUSB2
SIM ready
Waiting for Registration..(120 sec max)
Registered on Home network: "Free",2
Signal Quality: 12,99
now my router tp-link tl-mr3420 is working with sierracompass889
thank