Concatenated Short Message Service

Definition of Concatenated Short Message Service

Concatenated Short Message Service (CSMS) is a technology used to split and combine larger text messages that exceed the standard SMS character limit of 160 characters. It divides the long message into smaller segments, each sent as an individual SMS, and then reassembles them on the receiver’s device to display the message as a single, coherent text. This process enables users to send and receive longer text messages without manual intervention.


The phonetics for the keyword “Concatenated Short Message Service” are:/kənˈkatəˌnādəd ʃôrt ˈmesij ˈsərvəs/kən-KAT-ən-ay-dəd shôrt MES-ij Sər-vəs

Key Takeaways

  1. Concatenated SMS allows for sending longer text messages by dividing them into smaller parts, which are sent individually and reassembled upon reception.
  2. Each concatenated SMS message part is counted as a separate message for billing purposes and can consume multiple message segments depending on the encoding used.
  3. Concatenated SMS is compatible with almost all GSM devices; however, its successful delivery depends on the recipient’s device and network supporting the feature.

Importance of Concatenated Short Message Service

The technology term “Concatenated Short Message Service” (CSMS) is important because it allows for the sending and receiving of longer text messages beyond the standard 160-character limit of traditional SMS (Short Message Service). CSMS achieves this by breaking down a long message into smaller segments and reassembling them upon arrival at the recipient’s device.

This innovation in text messaging enhances communication by enabling users to share more detailed and extensive information in a single message.

Consequently, CSMS has played a vital role in improving the versatility, effectiveness, and convenience of mobile communication, paving the way for the evolution of messaging platforms that cater to the growing demand for more advanced features and functionalities.


Concatenated Short Message Service (CSMS) is a specialized feature within the realm of text messaging, fundamentally designed to extend the capabilities and enhance the user experience of SMS communications. Its primary purpose is to overcome the limitation of the standard text message length, which typically allows up to 160 characters for GSM (Global System for Mobile Communications) encoding, by enabling the sending and receiving of longer messages that seamlessly appear as a single, complete text to the recipient.

CSMS achieves this by automatically breaking down extensive messages into smaller, manageable segments and intelligently reassembling them on the recipient’s device, consequently allowing users to communicate more complex ideas or share detailed information without the constraints of the traditional SMS character limit. To achieve this functionality, the CSMS protocol assigns unique identifiers and sequence numbers to each of the segmented parts of a long message, thus ensuring that the recipient’s device can accurately reconstruct the message in its original form upon arrival.

This innovative solution provides users with a more convenient and efficient way to communicate through SMS, as the sender doesn’t need to manually divide the message into shorter parts, nor does the recipient have to piece together separate messages while attempting to comprehend their context. Ultimately, the Concatenated Short Message Service offers an enhanced, user-friendly version of SMS communication, enabling people to convey richer and fuller content within the familiar confines of the classic text message format.

Examples of Concatenated Short Message Service

Concatenated Short Message Service (CSMS) is a technology that allows the sending of longer SMS messages by splitting the content into multiple smaller messages, which are later reassembled by the recipient’s device. Here are three real-world examples of CSMS usage:

Emergency Alerts: During natural disasters or public safety emergencies, government agencies may send out urgent messages to affected populations. These messages often contain vital information and instructions that may exceed the standard 160-character limit for a single SMS. CSMS allows these alerts to be delivered in longer, more detailed formats by breaking them into smaller parts that are reassembled upon receipt.

Mobile Marketing Campaigns: Businesses often use SMS to send promotional content, offers, and updates to their customers. When a company needs to convey more information than a single SMS can contain, they may use CSMS to split the message into smaller segments and ensure it reaches the recipient as a complete, coherent message.

Personal Messaging: In everyday communication, people sometimes need to send lengthy text messages, which may exceed the standard character limit for an SMS. When sending such a long message, a smartphone typically employs CSMS to break the content into smaller parts, ensuring the entire message gets delivered to the recipient’s device seamlessly. The recipient then sees the full message, which appears as a single, uninterrupted text.

Concatenated Short Message Service FAQ

1. What is Concatenated Short Message Service (CSMS)?

Concatenated Short Message Service (CSMS) is a technology that allows sending longer SMS messages by splitting the text into multiple linked parts. These parts are reassembled by the recipient’s mobile device, displaying a single, coherent message.

2. How does CSMS work?

CSMS works by dividing a long message into smaller segments called “message parts.” Each part contains a User Data Header (UDH) and a reference number, indicating the total number of parts and the order in which they should be combined. When the recipient’s device receives these parts, it uses the reference number and UDH to reassemble the message into its original form.

3. What is the maximum length of a concatenated SMS?

The maximum length of a concatenated SMS depends on the encoding used. For GSM 7-bit encoding, each message part can have up to 153 characters, while for UCS-2 (Unicode) encoding, each part can have up to 67 characters. Consequently, a concatenated SMS with 3 parts has a maximum length of 459 characters in GSM 7-bit encoding or 201 characters in UCS-2 encoding.

4. Can all mobile devices support CSMS?

Most modern mobile devices support CSMS. However, older devices or those with limited SMS features may not support it. In such cases, the recipient may receive the message parts as separate, unintelligible SMS messages.

5. Are there any additional charges for sending concatenated SMS messages?

Charges for concatenated SMS messages depend on the mobile network provider and plan. Since the message is divided into multiple parts, each part may be billed as a separate SMS message. It is essential to check with your specific provider for detailed information on their charging structure.

Related Technology Terms

  • Fragmented SMS
  • Long SMS
  • Message Segmentation
  • Text Message Concatenation
  • User Data Header (UDH)

Sources for More Information


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