how to decode SMS User Data Header in text mode

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Honggo - 05 Jan 2004 14:59 GMT

I know we can do lot of things in PDU mode
but i just want to know
for the case of cocatenated sms
is it possible to decode User Data Header in text mode?
for example how to know which sequence is current SM
(1st, 2nd or 3rd SMS)
I know it could be done in PDU mode
but for some reason/constraint I need it done in text mode

in text mode (USER DATA field), i was getting something like
ù @¡d¡@
in User Data Header field (first few octates)
how to make use of this information without resorting to use PDU mode?

in PDU Mode itself, the UDH consist of
08 04 00 24 03 01

regards,
Honggo

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Peter_L - 05 Jan 2004 18:49 GMT

Hi

The problem is that the UDH is coded in 8Bit but text mode only works in
7Bit.
Now if a mobile receives a Concatenated SMS and you read it in text mode
then each byte of the UDH will be "seen" by the mobile as a 7Bit value and
will be converted to that character that matches to the selected character
set(using AT+CSCS, usually this is IRA).
With other words forget to use text mode to decode the UDH because wrong
characters will be output by the mobile if there are hex values above 0x7F
inside the UDH.
Or, check whether your mobile supports a 8Bit character set in text mode by
sending AT+CSCS=? to get a list of all supported char sets?

Hope that helps
Regards
Peter

> I know we can do lot of things in PDU mode
> but i just want to know
[quoted text clipped - 15 lines]
> regards,
> Honggo

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