Hi afshin
You have to chose the correct encoding format. The default encoding schema use for SMS is "
GSM default alphabet (GSM 03.38)[
^]" or this link
http://www.developershome.com/sms/gsmAlphabet.asp[
^]
This does not define Arabic character set.
Use AT+CSCS to set TE character set to support the correct encoding.
AT+CSCS=? to list all supported encodings. But please note, that not all GSM units/modem support all types of encoding.
To really make it the correct way. You have to switch SMS message format to PDU encoding via AT+CMGF command.
Via PDU format, you can select the correct encoding, make long SMS ( over 160 char ), sending pictures, ring tone etc...