Hi dears.
I want to send a string as sms in gsm modem witch mixed from english and unicode word.
for example:
"hello in persian is 'سلام' in arabic is 'السلام'."
now, how I can make a pdu format from this string and what change I have to make in my pdu format configuration?
Thanks alot if any one help me.

GSM modems don't create an interface between your pc and the gsm network; they get the hidden internet signals from the gsm signal

Sorry I dont understand your answer.
I am using the GSM Modem to sending and receiving sms.
there are 2 options for me.
1_sending in text mode
2_sending in pdu mode
I am using from pdu mode
in pdu mode I have to encode and decode sms.
english letter are 7 bit _Septet_ and persian or arabic letter are 8 bit _Octet_
and I confused how I have to encode them _when are mixed such as my example in first post_ to be able to realize sms after receiving and receiver be able too.
So, please explain more about your answer and help me more?

thanks but I saw it before.
I Coded my english message to octet.but realy I dont know how Ican do it when my message is made from persian word _that are 8 bit_.
in another style I have to encode a mixed message.
I dont know how I can do it.

I guess you must go for 16 bits for the mixed mode and use Unicode.

Cheers and Happy coding

So what will happens if my message be mixed from english and persian letters?
how I encode this example:
"hello in persian is 'سلام' in arabic is 'السلام'."
now english letters are 7 bit and arabic or persian ones are 8 bit.
I have to convert them to 16 bit?