The Maritime Mobile Service Identity is a unique, nine-digit number assigned to maritime radio communication equipment to facilitate efficient and automated communication in the Global Maritime Distress and Safety System (GMDSS). It is essential for identifying and addressing vessels, shore stations and other maritime entities in the international maritime communication network
In this blog, we will learn more about this maritime communication system: from purpose and components to structure and function.
Purpose and Components of the MMSI
Purpose:
To uniquely identify a ship, vessel group or coastal station during radio communication.
Enables digital communication systems like Automatic Identification Systems (AIS), Digital Selective Calling (DSC), and satellite systems to recognise the sender and receiver.
Components:
The Maritime Mobile Service Identity is composed of nine digits, structured to include information about the country and type of station.
The first three digits are the Maritime Identification Digits (MID), which indicate the country of registration.
Remaining digits: Unique to the vessel, station or entity.
Structure of MMSI:
The nine digits of this maritime communication system are structured in the following way:
Ship Stations: 3-digit MID, + six unique digits.
Group Calls: Begin with a leading ‘0’, followed by 3-digit MID and 5 unique digits.
Coastal Stations: Starts with a leading ‘00’, followed by MID and 4 unique digits.
Search and Rescue Aircraft: Begin with ‘111’, followed by the country code and specific identifier.
Functions of the Maritime Mobile Service Identity
Digital Identification: The MMSI acts like a ‘phone number,’ for maritime radios, identifying the sender and receiver.
Distress Calls: When a DSC-equipped radio sends a distress signal, the MMSI makes sure that the call is uniquely identified, which helps in rapid response.
Automatic Identification Systems (AIS): Used in AIS to track vessel movements and provide critical identification data to other ships and stations.
Communication with Shore Stations; Facilitates direct and group communications between ships and coastal authorities.
Satellite Communication: Used in satellite systems, like Inmarsat for efficient global communication.
How is the MMSI assigned?
National Authorities: These are assigned by the maritime authorities of the vessel’s flag state. In India, this is the Ministry of Shipping.
The process begins with an application, where shipowners or operators apply for an MMSI when registering their vessel’s radio equipment.
International Registry: MMSI information is also recorded in the International Telecommunication Union database to ensure global uniqueness.
Uses of the MMSI:
This maritime communication system has several uses, such as:
Commercial and Cargo Vessels: Essential for automated communication, tracking and safety.
Recreational Boats: Used for emergency alerts, and routine communication.
Search and Rescue Operations: It also helps identify the origin of distress calls and locate any vessels in need.
Port Operations: It helps enhance the coordination between ships and port authorities.
Benefits of Maritime Mobile Service Identity
Efficient Communication: Simplifies addressing in digital maritime systems, reducing manual errors.
Enhanced Safety: Rapid identification of vessels in distress.
Global Standardization: This allows for a smooth operation across international waters.
Integration with Advanced Systems: The maritime communication system also supports integration with AIS and other automated tracking systems.
Challenges with the MMSI
Misuse or Duplicate Assignments: Incorrect allocation or reuse of MMSI numbers can disrupt communication.
Lack of Awareness: Some small vessel operators may not understand the importance of obtaining and properly using an MMSI.
System Dependence: The effectiveness of MMSI depends on functioning radio and satellite systems.
International Regulations Governing the MMSI:
International Telecommunication Union (ITU): Establishes guidelines for MMSI structure, allocation and usage.
International Maritime Organisation: Ensures MMSI compliance within the GMDSS framework.
National Regulation: Maritime authorities ensure proper registration and adherence to international standards.
Conclusion
The Maritime Mobile Service Identity is an important part of modern maritime communication, as it ensures that vessels and maritime stations are uniquely identified for efficient and reliable communication. It plays a critical role in safety, navigation and operational efficiency, underpinning systems like the DSC, AIS and satellite communication. As maritime technology continues to evolve, the significance of MMSI in enabling automated and secure communication will only grow.
The Marine Engineering and the Nautical Science courses at the AMET Institute of Science and Technology provide training on various aspects of this maritime communication system, such as functionalities, regulations and applications. Students are trained in Global Maritime Distress and Safety System, where the MMSI is a fundamental component.
The students also receive practical training onboard the ships, allowing them to practice real-world MMSI operations, and learn more about the International Telecommunication Union. So if you want to learn more about the MMSI, then don’t wait, just join the AMET Institute of Science and Technology!
