SMPP Long Message With Charset iso88591 cut to 134 Character

Question

i have smpp direct connection to SMSC provider , i face problem when i send long english message with charset iso88591 the mobile receive it cut at 134 character only , Although I'm doing split the message into several parts before sending with correct UDH to every part .

so when i use charset 7bit i face problem with some character like @ $ & replaced with question marks but long message revived completed and concatenated correctly .

how to solve this problem?

Answer 1

1. From technological point of view, SMS per se is fixed size bit array 1120 bits long in the signaling halfduplex channel. which can be interpreted as 160 7- bit chars ( x 7 = 1120) or 140 octets (x 8 = 1120) or 70 UCS2 ( x 16 = 1120). If you use a message concatenation, the available capacity is decreased by size of UDH header.

2. Default alphabet in GSM network follows GSM 3.38 standard (as I wrote you already in my comment to another your question).

3. What I've met, GSM networks use 7 bit coding for english texts and UCS2 for another languages and 8 bit coding is used just for binary data e.g. for encrypted packets in GSM banking etc...

4. For english texts, we've always used 7bit coding with translation ASCII 7 <-> GSM 3.38 and I'd say this is the right way how to do it.

5. But we never used some 3rd party software in the middle: we've always talked to SMSC directly using one of few protocols used in the field.