Ap1.1.2 Inmarsat C Services - Furuno FELCOM 15 Service Manual

AP1.1.2 Inmarsat C Services

The Inmarsat C system provides the following communication services.
(1) Store-and-forward Telex message service
(2) EGC (Enhanced Group Call) broadcasting: Safety Net and Fleet Net
(3) Distress alerting and safety service
The following services are also available.
- Polling: The facility whereby an operational center sends a instruction to selected
MES, to perform a defined task, such as return a pre-assigned data report.
- Data reporting: Data report, such as ship's position is sent regularly to a terrestrial
subscriber.
- E-mail
Table AP1.1.3 lists each service of the Inmarsat system.
Service
Voice Available
FAX Available
Telex Available
Data
Available
communication
HSD
Available
Communication
Store-and-forward Telex service
The following briefly describes how a MES sends a ship-to-shore message.
1) When the MES sends a message, it transmits a channel assignment request to the
LES. Then, the LES assigns the channel to the MES. After receiving a channel
assignment, the MES starts transmitting the message in packets.
2) The LES stores the received message and reconfigured the message. The LES
checks the received packets for errors, and if it finds any, returns acknowledgement
packets identifying the packets in error to ask to send the message again. The
reconfigured message is send to the intended destination via public network.
3) When the land subscriber sends the message, LES sends the message in packets to
MES. The MES checks the received packets for errors, and if it finds any, returns
acknowledgement packets identifying the packets in error to ask to send the
message again. The MES stores the received message and reconfigured the
message to output.
Table AP1.1.3 Comparison of each Inmarsat sytem service
A B
Available
Only sends
TEXT to PSTN
Available
for Ship to Shore
direction.
Available
Available Available (DNID)
Available
AP1-3
Inmarsat system
C
Not available Available
Available
Available Not available
Available
Not available Not available
AP1.1 System Overview
M Mini M
Available
Available
Not available
Available
Not available