I used Dongle for standby line and using following config to receive SMS even Chinese is OK. SMS will be email out to mailbox.
[from-trunk-dongle]
exten => sms,1,Noop(Incoming SMS from ${CALLERID(num)} ${BASE64_DECODE(${SMS_BASE64})})
exten => sms,2,System(echo "Subject: SMS received from ${CALLERID(num)}" > /var/log/asterisk/smsmail)
exten => sms,3,System(echo " " >> /var/log/asterisk/smsmail)
exten => sms,4,System(echo '${BASE64_DECODE(${SMS_BASE64})}' >> /var/log/asterisk/smsmail)
exten => sms,5,System(sendmail -f XXXXXX@gmail.com -t XXXXXXX@gmail.com < /var/log/asterisk/smsmail)
exten => sms,n,System(echo '${STRFTIME(${EPOCH},,%Y-%m-%d %H:%M:%S)} - ${DONGLENAME} - ${CALLERID(num)}: ${BASE64_DECODE(${SMS_BASE64})}' >> /var/log/asterisk/sms.txt)
exten => sms,n,Hangup() |