Just like your brand messaging hierarchy in other areas of your marketing strategy, the anatomy of a SMS and MMS message are important and can influence the performance of your message and how it is perceived.
But what’s the big deal? Is there really a correct and incorrect way to draft a text message campaign? There actually is no wrong answer, but there are ways to optimize your campaigns with specific message formulas.
First, we’ll cover the building blocks of what every SMS and MMS campaign message has on the screen, then we will also take a look under the hood to understand the technical infrastructure.
The Anatomy of an SMS Message
SMS messaging is the earliest and most widely used messaging service, is a text-based communication method over cellular networks. An SMS message is more than just the text you see on your screen; it involves several components working together seamlessly.
Let’s review and simply what you will see on the screen as well as talk about what goes on behind the display so you can get a more clearer picture of the technical backend.
On-Screen Components (Visible to the User)
These are the elements that the user directly interacts with or sees on their device when you send a text message campaign:
- Sender and Receiver Information:
- Your Number: If you are in the US, that would be +1 followed by a 7-digit number, toll free number or it can even be a 6-digit short code. Did you know that the more technical term for your phone number is your Mobile Station International Subscriber Directory Number (MSISDN). It was a term created by The International Telecommunication Union (ITU), the organization responsible for creating the MSISDN standard. How cool is that?
- Message Content: This is the primary content the user sees, including the text of the message.
That part is pretty simple, it’s just your number and the message content, an experience you are well familiar with. Have you ever thought about what components are in the back-end? Let’s review!
Backend Components (Invisible to the User)
These are the elements that work behind the scenes to deliver the message:
- Service Center (SMSC):
- SMSC Address: is a network component that stores and forwards SMS messages between mobile devices. SMSC acts as a relay point, but its address is typically not displayed to the user.
- Protocol Data Unit (PDU): is a standardized unit of data that defines the structure of an SMS message, including its type, recipient, sender, and content. It includes:
- PDU Type: This determines the direction of the message (inbound or outbound).
- Message Reference: Used for tracking and error handling.
- Address Length: Indicates the length of the recipient’s number.
- Destination Address: The recipient’s MSISDN.
- Protocol Identifier (PID): For specific protocols, if applicable.
- Data Coding Scheme (DCS): Determines character encoding and message type.
- Validity Period: Sets a time limit for delivery.
- User Data:
- User Data Length: The length of the message content.
- User Data Header (UDH): For features like message concatenation.
In summary, the on-screen components primarily involve the message content and the visible sender and receiver information, while the backend components handle the technical aspects of delivering the message, such as routing, tracking, and encoding.
The Anatomy of an MMS Message
MMS extends the capabilities of SMS by allowing multimedia content like images, audio, and video. An MMS message comprises several components that ensure rich content delivery.
On-Screen Components (Visible to the User)
- Sender and Receiver Information
- Your number: No matter if it’s an SMS message or a MMS message, this part of the anatomy remains the same.
- Media Content: This can come in many formats based on your engagement strategy!
- Attachments: Images, photos, graphics, audio, video, and gifs.
- Text: This is your message body and can include emojis, numbers and letters.
Also one really cool thing about MMS messages offers more message body limits unlike the size limits SMS messages may have. MMS message limits vary depending on your carrier and the type of content you’re sending (e.g., images, videos, audio).
Generally, carriers impose limits on the total size of an MMS message, including the text content and any attached multimedia files. These limits are in place to manage network traffic and ensure efficient delivery of message
Backend Components (Invisible to the User)
These are the elements that work behind the scenes to deliver an MMS message:
- Message Header:
- MMS Version: The specific MMS protocol version.
- Message-ID: A unique identifier for the message.
- Content-Type: Specifies the type of content (e.g., multimedia).
- Message Body:
- Content-Disposition: How the content should be displayed.
- Content-Length: The size of the message.
- Content-Transfer-Encoding: The encoding format.
- Media Content:
- SMIL (Synchronized Multimedia Integration Language): A markup language describing the multimedia content and how it should be presented, often as a slideshow.
- Additional Information:
- Read-Report: Indicates if a read receipt is requested.
- Delivery-Report: Indicates if a delivery receipt is requested.
- Expiry: Sets a time limit for the message.
While many of these backend components are similar to SMS, MMS introduces additional elements to handle multimedia content and more complex message structures.
Why Understanding SMS and MMS Structure Matters
Grasping the intricacies of SMS and MMS is not only fascinating but also crucial for businesses and developers who leverage these technologies. From marketing campaigns to customer service, understanding how these messages are constructed can enhance effectiveness and reliability.
SMS and MMS are integral to our mobile communication ecosystem. While SMS offers simplicity and ubiquity, MMS provides the richness of multimedia content. By dissecting the anatomy of these messages, we gain insight into the sophisticated technology that enables our everyday communication.
Whether you’re a tech enthusiast, a developer, or a business professional, appreciating the complexity behind these seemingly simple messages can open up new possibilities for innovation and connectivity.
