MMS/SMS decompression

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Jonas B. Jacobi - 30 Oct 2003 20:19 GMT

Hi Folks!
I have some questions concerning MMS.
When sending a MMS to someone, he/she is getting a SMS containing the
information where to get the MMS from, right?
I'm in the situation that i get such SMS and want to decode/decompress it to
get the servername.
Am i right, that these SMS messages are compressed according to ETSI 03.42?
And to get it's contained informations, i have to decompress it according to
ETSI 03.42, or is there something else to do?

TIA,
Jonas

PS:Please excuse my poor english.

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John Henderson - 31 Oct 2003 22:59 GMT

> Hi Folks!
> I have some questions concerning MMS.
[quoted text clipped - 5 lines]
> And to get it's contained informations, i have to decompress it according to
> ETSI 03.42, or is there something else to do?

You might find useful documentation on the
http://www.openmobilealliance.org/documents.html site.

Low-level MMS is not something I've got around to doing myself,
so I can't help you with practical suggestions.

John

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Peter_L - 03 Nov 2003 18:19 GMT

Hi Jonas

Yes, so far I know you just need to uncompress the SMS message according to
GSM 03.40.
Several 7bit characters are packet into 8Bit octets, you need to unpack
these 7Bit chars out of the octets.

If you can operate your mobiles via AT Commands and it supports text mode
then you can let the mobile do the job for you by sending:
AT+CMGF=1 switch on text mode
AT+CMGR=x read SMS where x is the memory location of the SMS
Then the mobile should output the SMS in plain text.

Regards
Peter

> Hi Folks!
> I have some questions concerning MMS.
[quoted text clipped - 10 lines]
>
> PS:Please excuse my poor english.

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John Henderson - 03 Nov 2003 19:22 GMT

> Yes, so far I know you just need to uncompress the SMS message
> according to GSM 03.40.
> Several 7bit characters are packet into 8Bit octets, you need
> to unpack these 7Bit chars out of the octets.

If you need it, the packing algorithm (between septets and
octets) is given in GSM 03.38.

John

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