A concatenated short message service is used to overcome the limit on the number of characters that can be sent in a single SMS text message transmission (usually 160 chars). With this method, the sending device divides the long message into smaller ones that get recombined at the receiving end, with each message charged as a single SMS message.
With this feature, the complete message appears to the receiving user as a single long text message (a concatenated SMS message). On networks which do not support Concatenated SMS, each smaller message is delivered as individual SMS text message.
Concatenated message character count is reduced by 7 characters per message. Messages longer than 160 characters are reduced to 153 characters, while messages outside the GSM-7 character set (i.e. Unicode) are reduced from 70 to 67 characters.