Siemens MT50 and AT Commands

Hi! I have Siemens MT50. I have a cable to serial connection too. I
want to send sms via terminal on my PC. I tried do it with use AT
Commands and I had a few problems. First. I may write commands only in
PDU mode. When I try send AT+CMGF=1, my mobile return error. Second.
When I try send sms in PDU mode, mobile return error too.
I write on terminal and send to mobile next commands:

AT+CMGS=28

when mobile return ...> I send:

00 11 00 0B 91 84 07 28 15 53 F8 00 00 AA 0A E8 32 9B FD 46 97 D9 EC
37<ctrl-z>

after a few seconds mobile return ERROR. I do not know why.

It is possible sending sms via serial terminal and AT Commands in
Siemens MT50?

Maybe someone did it.