Subelement C: Satellite Systems— Topic :
Question 30C3
Element 9 (GMDSS Maintainer)What is the meaning of the “ACB” Inmarsat-C Non-Delivery Notification (NDN) failure code?
Explanation
The Inmarsat-C Non-Delivery Notification (NDN) failure code "ACB" specifically stands for "Access Barred." This indicates that the Inmarsat system has actively prevented the user's terminal or account from establishing communication. This can occur for various administrative reasons, such as non-payment for services, suspension of the account, or unauthorized access attempts. It's a system-level restriction on the ability to use the network.
Option A describes a problem with the destination's response, not an Inmarsat access issue. Option C refers to a bit error rate, which relates to signal quality, not an administrative access block. Option D points to a technical failure within a message channel, which is different from being barred from using the system altogether.
Related Questions
30C1 Which of the following conditions would prevent communications between an Inmarsat-C data port and external data terminal equipment (DTE)?30C2 How can a LES/RCC (Rescue Coordination Centre) determine if an Inmarsat-C Distress Alert is a TEST transmission?30C4 What condition can indicate a communication failure between the second receiver (RX2) and the Antenna Control Unit (ACU) in an Inmarsat Fleet 77 terminal?30C5 Which of the following devices can cause interference to Fleet 77/55 systems?30C6 What error message may be displayed if a connection to the Inmarsat Mobile Packet Data Service (MPDS) network fails?