CODEWITHSUNDEEP
sms
Hakkaino
Hakkaino

Reputation: 1

SMS PDU Concatenation

I am working with SMS Concatenation. My GSM Modem supports PDU Mode. My UDH works fine when i use the IEI for 05 for using a certain port but then i tried using IEI 00 which is for concatenation. I am receiving the two messages combined as single message without problem but i am receiving unreadable sms of weird characters. Below is my PDU for the first part.

0041000B819062972624F60000A0050003A1020154741914AFA7C76B9058FEBEBB41E6371EA4AEB7E173D0DB5E983E8E832881DD6E741E4F7D905A2A2CBA0783D3D5E83C4F2F7DD0D32BFF12075BD0D9F83DEF6B21C44479741ECB03E0F22BFCF2E10155D06C5EBE9F11A2496BFEF6E90F98D07A9EB6DF81CF4B697E5203ABA0C6287F57910F97D7681A8E832285E4F8FD720B1FC7D7783CC6F

and this one is for the second part:

0041000B819062972624F600007B050003A102027890BADE86CF416F7B590EA2A3CB2076589F0791DF6717888A2E83E2F5F4780D12CBDF7737C8FCC683D4F5367C0E7ADBCB72101D5D06B1C3FA3C88FC3EBB4054741914AFA7C76B9058FEBEBB41E6371EA4AEB7E173D0DB5E9683E8E832881DD6E741E4F7D905

Thanks a lot for helps in advance.

Upvotes: 0

Views: 3003

Answers (1)

KeyszerS
KeyszerS

Reputation: 684

Did you remember to pad your UDH with additional bits so that your UD septets that follow start on a septet boundary?

If for example you have 6 octets in your UDH (most common), which equals 48 bits, then you have to add 1 more bit so that the GSM-7 encoded characters start on a septet boundary (49 bits is 7 septets).

Read http://mobiletidings.com/2009/02/18/combining-sms-messages/ for more information.

Upvotes: 1

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