Furuno Felcom 50, Руководство оператора

Страница: 194 / 203

9. SYSTEM DESCRIPTION
9-2
System satellites
The satellites are positioned in a geostationary orbit above the equator at
approximately 35700 km altitude. See figure below.
In geostationary orbit, each satellite moves at the same rate as the earth, and so
remains in the same relative position to the earth.
The satellites provide 99% landmass coverage.
FELCOM 50 can communicate via the four satellite Ocean Regions:
AOR-W Atlantic Ocean West Region
AOR-E Atlantic Ocean East Region
IOR Indian Ocean Region
POR Pacific Ocean Region
The coverage area of the satellites for FELCOM 50 is shown on page 3-4.
Transmission frequencies
The Inmarsat terminals operate in the following frequency bands:
•
MES transmission frequencies:1626.5 MHz - 1646.5 MHz
•
MES receiving frequencies:1530.0 MHz - 1559.0 MHz
EQUAT
O
R
EA
RT
H
120
00 k
m
357
00 k
m
Pacific Ocean Region
Indian Ocean Region
54˚W
64.5˚E
178˚E
15.5˚W
Atlantic Ocean Region (West)
Atlantic Ocean Region (East)
Satellite positions.
A large number of channels are available (20 kHz channel separation), offering
either 4.8 kbps voice communication, as well as 9.6 kbps fax or 64 kbps data
communication.
Duplex communication uses two channel frequencies, one in each direction.
The LESs provide interface to the international networks for telephony and data:
PSTN (Public Switched Telephone Networks) and PSDN (Packet Switched Data
Networks).