Fbus protocol problem

[hinbun]

Dear All,

Nice to meet all! I was come from Hong Kong which is a student which doing a school project about using MCU AT89S52 to control Nokia 6150(FBus) to send and receive SMS. I already made the circuit and successful send and receive data through HyperTerminal

I downloaded a protocol for Nokia 6150, I have some problem would you mind give me a help?

According "Frame format for FBUS", I am not very clear how to using following fields.

<1 byte FrameID><1 byte destination><1 byte source><1 byte cmd><2 bytes data length (= n + 2 )><n bytes data><1 byte frame to go><1 byte sequence number><2 bytes checksum>

data length - The length is the data before pack into byte or is the length after pack into byte?
Padding Byte - This field is depend on the lenght of data or whole frame(i.e.FrameID to checksum)?
frame to go - I do not know when is need this field. If the packet is not a part of a group(long sms), is it no need to including this feild?

The last question is how to synchronize to the phone, I readed website embedtronics about Nokia F-bus Protocol. It say synchronize to the phone by sendind a string of 0x55 or 'U' 128 times, but i can not successful synchronize. I have follow question.

1. Sending the 128 times 'U', is it also need send a whole FBus packet?? i.e. it is need the other field <1 byte FrameID><1 byte destination><1 byte source><1 byte cmd><2 bytes data length (= n + 2 )><1 byte frame to go><1 byte sequence number><2 bytes checksum>?
2. It is need pack 128 'U' into byte or not? That is, not send 0x55 128 times, send (0xD5,0x6A,0xB5,0x5A,0xAD,0x56,0xAB) x 16 times?
3. If need sending a whole packet, what the cmd should use for synchronization?

I was stuck on synchronize to the phone, I am very need all you help!!! Thank you!!

Bun