An extension to the short message service (SMS) that allows messages longer than 160 alpha-numeric characters with 7-bit character encoding to be sent using a mobile phone.The longer concatenated SMS text messages are broken down and sent as multiple smaller messages. The recipient's mobile phone assembles the messages back into one long message.
PDU Mode SMS
In technical terms, the concatenated SMS could also be referred to as a PDU Mode SMS. The number of parts that a multi-part or PDU mode SMS message may contain depends technically upon a header message but mostly upon the device sending or receiving the SMS and also upon the service provider.