Aftab
Date: Thu, 12 Feb 2004 11:53:22 +0530 From: "Navjot Singh" <[EMAIL PROTECTED]> Subject: RE: UDH for long sms To: <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="iso-8859-1"
In general, UDH is like this.
1 byte - udh length ( 0b i.e 11 bytes that follow) 2 byte - info element id ( 05 - port addressing scheme i.e. 16 bit port) 3 byte - ifo element len ( 04 ) 4 byte - higher order byte of destination port 5 byte - lower order byte of destination port 6 byte - higher order byte of source port (usually set to 00) 7 byte - lower order byte of source port (usually set to 00)
8 byte - info element id ( guess 00 is for concatenated sms) 9 byte - info element len ( 3 in our case as we have 10,11,12) 10 byte - info element reference number (ref number for for long sms) 11 byte - info element data (total/max number of sms parts) 12 byte - info element data (current part of total sms parts)
Say you have 300 bytes of (8 bit) data to send. Say byte 11 is set to 3 then 12th byte can take values 1,2,3. and you MUST keep SAME value in 10th byte for all 3 parts.
Additionally,
You need 12(UDH) + 1-128(Data) as you an 140 bytes in one request. You need 12(UDH) + 129-256(Data) in second request. You need 12(UDH) + 257-300(Data) in third request.
To send concatenated SMS, i think you don't need bytes from 2 to 7. So, the equations change accordingly.
Hope this helps. Geeks can correct me if i am wrong somewhere. Am still a novice.
Navjot Singh
