海上移動服務身分(MMSI)

Maritime Mobile Service Identity (MMSI)
海上移動服務識別碼(MMSI)

尚作仁船長 編譯

 

What is Maritime Mobile Service Identity (MMSI)?
什麼是海上移動服務識別碼(MMSI)?

Maritime Mobile Service Identity(MMSI) is a unique, 9-digit number assigned to a digital selective calling (DSC) radio. It acts as a digital fingerprint for vessels, making it easier for other boats and authorities to identify and communicate with a ship at sea quickly.The International Telecommunications Union (ITU)in Geneva allocates, manages, and regulates MMSIs.
海上行動服務識別碼(MMSI)是分配給數位選擇性呼叫(DSC)無線電的唯一9位數號碼。它充當船舶的數位指紋，使其他船隻和當局能夠更輕鬆地快速識別海上船舶並與其通訊。

 

The Structure of an MMSI Number
MMSI號碼的結構

There are two parts to an MMSI number:
MMSI號碼由兩個部分組成：

· The first three digits are the maritime identification digits (MID), identifying the country that issued the number.
前三位數字是海事識別數字(MID)，用於識別頒發該號碼的國家。

· The last six digits are the Mobile Station Identifier (MSI), which can be any number from 0-9, and is unique to a vessel or radio.
最後六位數字是行動站識別碼(MSI)，可以是0-9之間的任何數字，並且對於船舶或無線電設備來說是唯一的。

 

Who Needs an MMSI?
誰需要MMSI？

Any ship that is required to carry a VHF radio with DSC capabilities needs an MMSI. This includes most vessels over 20 meters in length, as well as some smaller vessels, depending on the country’s regulations. Other maritime objects – such as fixed offshore installations, mobile units, and maritime aircraft – may also be assigned MMSIs.
任何需要攜帶具有DSC功能的VHF無線電的船舶都需要MMSI。這包括大多數長度超過20公尺的船舶，以及一些較小的船舶，具體取決於國家/地區的法規。其他海上物體—例如固定海上設施、移動裝置和海上飛機—也可能被分配MMSI。

All vessels participating in the International Maritime Organization’s (IMO)Global Maritime Distress & Safety System (GMDSS)must have an MMSI. As a key maritime communication feature, the GMDSS establishes an internationally accepted framework for coordinated VHF radio communications among merchant vessels. It ensures continual and synchronized contact between multiple ships, or between ships and shore operators through satellite and terrestrial networks.
所有參與國際海事組織(IMO 全球海上遇險與安全系統(GMDSS)的船舶都必須擁有MMSI。作為一項重要的海上通訊識別碼，GMDSS為商船之間協調特高頻無線電通訊建立了國際公認的架構。它確保多艘船舶之間或船舶與岸上運營商之間透過衛星和地面網路進行持續、同步的聯繫。

 

What is the Purpose of an MMSI?
MMSI的目的是什麼?

The primary purpose of an MMSI is to provide a standardized and unique identifier for maritime entities, enhancing safety, communication, navigation, and regulatory compliance in the maritime domain.
MMSI的主要目的是為海事實體提供標準化且唯一的識別識別碼，從而增強海事領域的安全、通訊、導航和監管合規性。

A ship’sautomatic identification system(AIS) transponder transmits the MMSI every 30 seconds. This information can be accessed by Vessel Traffic Services, shore stations, the Coast Guard, and other ships with access to AIS equipment.
船舶的自動辨識系統(AIS)應答器每30秒傳送一次MMSI。船舶交通服務、岸站、海岸警衛隊和其他可使用AIS設備的船舶均可以存取此資訊。

MMSI provides a unique identification number for each maritime entity, ensuring that no two share the same identifier. This allows for precise identification in maritime communication and tracking systems.
MMSI為每個海事實體提供唯一的識別號，確保沒有兩個實體共用相同的識別碼。這使得海上通訊和追蹤系統能夠進行精確識別。

It is also a fundamental component of the AIS, used for real-time vessel tracking and collision avoidance. The MMSI is transmitted as part of the AIS signal, enabling vessels to be identified and tracked by other vessels and maritime authorities.

它也是AIS的基本組成部分，用於即時船舶追蹤和避碰。MMSI作為AIS訊號的一部分進行傳輸，使其他船隻和海事當局能夠識別和追蹤船隻。

MMSI is used in DSC, a method of initiating digital communication between ships, or between ships and shore stations. It allows ships to send and receive distress calls, position reports, and other messages directly to other vessels with DSC radios.
MMSI用於DSC，這是一種在船舶之間或船舶與岸站之間啟動數位通訊的方法。它允許船舶透過DSC無線電直接向其他船舶發送和接收遇險呼叫、位置報告和其他訊息。

In emergency situations, such as distress or man-overboard incidents, MMSI facilitates quick and accurate identification of the distressed vessel. Search and rescue authorities rely on MMSI to locate and coordinate assistance efforts.
在緊急情況下，例如遇險或人員落水事件，MMSI有助於快速且準確地識別遇險船隻。搜救機構依賴MMSI來定位和協調援助工作。

Lastly, using MMSI helps with efficient traffic management by allowing maritime authorities to monitor vessel movements, prevent collisions, and manage the flow of maritime traffic in busy waterways.
最後，使用MMSI有助於海事當局監控船舶運動、防止碰撞並管理繁忙水道中的海上交通流量，從而有助於高效的交通管理。

 

The Difference Between an MMSI Number and an IMO Number
MMSI號碼和IMO號碼之間的差異

MMSI and IMO numbers are both used for identification purposes in the maritime industry, but they serve different functions and are assigned by different organizations.
MMSI和IMO號碼均用於海運業的識別目的，但它們具有不同的功能並由不同的組織分配。

 

MMSI
移動用戶識別碼

· Function: MMSI is primarily used to identify and address radio communication equipment on a vessel. It is also used in systems like VHF radio, AIS , and satellite communication.
功能： MMSI主要用於識別和尋址船上的無線電通訊設備。它也用於VHF無線電、AIS和衛星通訊等系統。

· Assignment: MMSI numbers are assigned by national authorities responsible for maritime communications in each country. They are typically obtained by vessel owners or operators.
分配：MMSI號碼由各國負責海事通訊的國家當局分配。它們通常由船東或經營者申請獲得。

 

IMO Number
國際海事組織編號

· Function: the IMO number uniquely identifies ships. It is a seven-digit number that remains with the vessel throughout its life, regardless of changes in name, ownership, or flag. This is particularly important for ships engaged in international trade.
功能：IMO編號是唯一的船舶標識。這是一個七位數的號碼，在船舶的整個生命週期中一直保留不變，無論名稱、所有權或旗幟如何變化。這對於從事國際貿易的船舶尤其重要。

· Assignment: IMO numbers are assigned by the International Maritime Organization (IMO), a specialized agency of the United Nations responsible for regulating shipping. The numbers are assigned to ships over 100 gross tons and certain types of smaller vessels.
分配：IMO編號由國際海事組織(IMO)分配，該組織是聯合國負責管理航運的專門機構。這些編號分配給總噸位超過100的船舶和某些類型的小型船舶。

 

MMSI and Deceptive Shipping Practices
MMSI和欺騙性海運行為

Bad actors are involved indeceptive shipping practices that manipulate the uniqueness of the Maritime Mobile Service Identity number for their illicit purposes. This is especially true when it comes to AIS handshakes, AIS gaps, and flag hopping.
不良行為者參與欺騙性海運行為，操縱海事移動服務識別號碼的唯一性以達到非法目的。當涉及到AIS握手、AIS間隙和跳旗時尤其如此。

AIS handshakes involve two vessels, typically a “clean” one with a legitimate identity and a “dirty” one engaged in illegal activities, such as smuggling or sanctions evasion. They engage in a secret exchange of AIS transponders, essentially swapping identities. The “dirty” vessel transmits its MMSI and other data to the “clean” one, effectively taking on its identity. The “clean” vessel then transmits its information to the “dirty” one, completing the swap.
AIS握手〔註〕涉及兩艘船，通常一艘具有合法身份的「乾淨」船和一艘從事走私或逃避制裁等非法活動的「骯髒」船。他們秘密交換AIS應答器，本質上是交換識別碼。「髒」船將其MMSI和其他資料傳輸到「乾淨」船，從而有效地獲取其身份。然後，「乾淨」的船將其資訊傳送給「髒」的船，完成交換。

〔註〕握手(Handshake)在電信和微處理器系統中具有以下含義：

1. 在資料通訊中，由硬體或軟體管理的事件序列，在進行資訊交換之前，需要對操作模式的狀態互相達成協定。

2. 在接收站和傳送站之間建立通訊參數的過程

Manipulating the MMSI misleads other vessels, authorities, or systems relying on AIS data for tracking.
變造MMSI會誤導依賴AIS資料進行追蹤的其他船隻、主管當局或系統。

Similarly, with AIS gaps, the weak or turned-off transponder signal can be exploited by vessels engaging in deceptive shipping practices. They may try to avoid detection by pausing the AIS broadcast or transmitting false MMSI information.
同樣，由於AIS存在資訊間隙，信號微弱或關閉AIS應答器，可能會被從事欺騙性海運行為的船舶利用。他們可能會嘗試透過暫停AIS發射或傳輸虛假MMSI訊息來避免偵測。

Flag hoppinginvolves a vessel rapidly changing its flag registration to bypass regulations, evade sanctions, or hide its illicit activities. When a vessel changes flags, it requires anew MMSI, because the MID is different for every country. This can make it difficult for authorities to track the vessel’s history and identify its previous activities under different flags, potentially hindering investigations and enforcement efforts.
跳旗涉及船舶快速改變其旗幟註冊，以繞過法規、逃避制裁或隱藏其非法活動。當船舶更換旗幟時，需要更新MMSI，因為每個國家的MID都不同。這可能使主管當局難以追蹤該船的歷史，並辨識其先前在不同旗幟下的活動，這可能會阻礙犯罪調查和執法工作。