Concatenated Short Message Service, often abbreviated as Concatenated SMS, is a technique used to send longer text messages by dividing them into smaller segments or parts. These parts, often referred to as concatenated segments, are then sent individually and reassembled at the recipient's end to display the complete message.

The need for Concatenated SMS arises because traditional SMS has a character limit (e.g., 160 characters for standard GSM 7-bit encoding). When a message exceeds this limit, it is split into multiple parts, each accommodating the allowed number of characters. These parts are then sent to the recipient sequentially.

At the recipient's end, the mobile device reassembles the concatenated segments to present the message as a whole. This process is transparent to the user, and they receive the complete message without any indication of the segmentation.

Concatenated SMS is particularly useful when sending lengthy messages, such as notifications, alerts, or information, where fitting the entire content within the character limit is not possible. It ensures that recipients receive the intended message without any critical information being omitted.

Understanding Concatenated Short Message Service is important for businesses and developers using SMS as a communication channel. It allows for effective message delivery, especially when conveying detailed or lengthy information to recipients, enhancing the communication experience.