RSS Feed
This is an automatic calling system which makes the initial contact between two stations, group of stations or station in a selected area. The caller composes of a short message which is transmitted to the receiving stations. Dedicated radio frequency have been allocated for this purpose in the VHF, MF and HF bands for short, [...]
Archive for the ‘Communication’ Category
The Digital Selective Calling (DSC) System
Posted by author on July 15th, 2008
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Satellite Acquisition
Posted by author on July 14th, 2008
To operate any Inmarsat equipment it is essential to acquire the satellite signal and lock on to that signal before the equipment can operate. In principle, the satellite has to be acquired either manually or automatically by pointing the antenna accurately towards the satellite for the chosen ocean region.
Inmarsat C equipment uses a small Omni-directional [...]
Inmarsat Fleet F77 Service
Posted by author on July 13th, 2008
Inmarsat F77 brings a new dimension to Inmarsat provisions of GMDSS services by offering call prioritization to 4 levels and real time hierarchical call pre-emption in both directons.
Inmarsat F77 is capable of meeting the criteria of four levels of priority:
· Distress
· Urgency
· Safety
· Other communications
It give appropriate access for communication in both ship-to-shore direction and [...]
Inmarsat Fleet F55 Service
Posted by author on July 13th, 2008
Fleet F55 is a single integrated voice, fax, and data service which offers a choice of communication option. There some fundamental differences between the two form of communication suiting different types of operational needs:
Mobile ISDN for voice, fax, large files transfer and facilities such as videoconferencing.
Mobile Packet Data Service (MPDS), allowing end-users to remain always [...]
Inmarsat Fleet F33 Service
Posted by author on July 13th, 2008
The fleet F33 is the latest addition to the fleet family. It has a single integrated voice, fax and data service offers a choice of communication including:
An integrated data service connecting at a speed of 9.9kbits/sec within the spot beam, fax and batched transmission such as file transfers.
The Mobile Packet Data Service (MPDS) allows end-users [...]
