FLEET -
77
VASUDEVAN PONDICHERRY PH: 91 96299N80476 E MAIL: vasurc@gmail.com
What services are offered by fleet-77?
Mini-M
voice, fax, Data, 3.1 KHz audio speech, ISDN 56/64/128 Kbits/s, MPDS
(ISDN-
Integrated Services Digital Network,
MPDS-
Mobile packet Data Service)
What are the advantages of fleet-77?
prioritization
and preemption
What is the power output (EIRP)?
32dbW
What is the speed of transmission?
Mini-M
voice
fax,
Data
3.1 KHz audio speech
ISDN 56/64/128 Kbits/s
MPDS
Type of aerial? Size of the aerial?
Highly
directional parabolic dish antenna Height 108 cm, 91 cms in dia
Why such type of antenna is is used?
For
voice communication
What is pre-emption?
Over
riding the lower priority call by the higher priority call while lower priority
call on progress in the same LES from ship to shore or ship to shore direction
(that means both directions, pre emption is possible)
What is prioritization?
Call
prioritization
Distress
call has higher priority than urgency and safety priority calls
Urgency
call has higher priority than safety and routine priority
Safety call has higher priority than routine priority
What are the
4 levels of priority?
P3 will pre-empt all other communications
P2 will pre-empt P1 and P0 calls
P1 will pre-empt P0 calls
(It
has ISPS code.
International
ship and port Facility Security code)
How do you inform URGENCY or SAFETY
messages?
By
using two digit special access code
In
Fleet 77, priority selection is also available
What is SNAC?
Single
Network Access Code
The
same code is used for telephone contact in all four ocean regions .
SNAC:
870
FLEET 77 BDU CONNECTIONS:
NMEA
input – Telephones
NMEA
– GYRO and NAVIGATION Interface
Connect
to GPS antenna
MPDS
network – LAN to Computer (RS232)
ISDN
– connection to ISDN equipment
RJ11
– FAX/analogue phones
RJ1
– Mobile phone
Handsets
Discrete
to INPUT/OUTPUT
Power
connections – 24 V DC power supply
USB
Interface – connect to PCs
Why FLEET 77 is called as FLEET 77?
(FLEET
77, FLEET 55 are the same group system)
The
first of fleet systems was the77 cm maritime antenna.
Hence
it is known as FLEET 77
How the charges are calculated?
SAT
C is calculated as per the size of the message
SAT
B TELEPHONE, SAT B TELEX
And
FLEET 77 telephone are calculated as per the duration
