Globalstar MCM-4M, Инструкция по установке и эксплуатации

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G l o b a l s t a r M C M - 4 M O P E R A T I O N
1-1
1. Operation
Your Multi Channel Modem System is easy to use, versatile, and dependable. When configured properly, all
4 channels can be combined to provide an aggregate Internet connection equivalent to a 28 Kbps modem.
If two, three or 4 units are available and configured for cascaded operations you can achieve an aggregate
Internet connection equivalent to a 112 Kbps modem. Internet access is available in all Globalstar™
network data services coverage areas except those for China and Nicaragua.
WARNING - The transmitted RF field intensity at the surface of the transmitting antenna is
fairly high. Do not use when someone is within 29 inches (0.74 meters) of the antenna.
1.1. Basic Satellite Information
Globalstar satellites operate in an inclined orbit of 52 degrees. They come up over a point on the
western horizon, move across the sky, and then drop behind the eastern horizon. The average user
cannot predict the path of the satellites. Each satellite will pass from horizon to horizon in about 10-15
minutes. When the MCM-4M is located in moderate latitudes (22-52 degrees) it will communicate with
at least TWO satellites passing over your geographic location.
This system uses high frequency microwave signals. Unlike television and AM or FM radio signals, or
even cellular phone signals, microwave radio signals do not bend and are strictly line of sight. This
means that these signals do not go through, or around, dense objects including the platform’s own
superstructure, wings or masts. It can not go through, or around, other objects adjacent to the
platform either (trees, buildings, overhangs, cranes, tall hills or mountains). If something gets between
the satellite and the antenna the data connection won’t work until another satellite (which is not
blocked) is received or the platform moves to a location where your antenna will no longer be blocked
by the object. If the antenna is no longer pointed up toward the overhead location of the satellites, the
data connection won’t work until the antenna has a clear view of the sky above again.
If the MCM-4M antenna’s view of the sky above 10
o
elevation is restricted, the unit will suffer
temporary data rate reductions. If the antenna is completely blocked, the signal to/from the satellite
will be lost until the signal path is unobstructed.
1.2. Key Points About Your Equipment
The MCM-4M provides you with data access over the Globalstar satellite network. In some
geographic areas setup, configuration and usage may be slightly different. Subject to certain constraints,
the MCM-4M is capable of dial up packet or asynchronous operation in any Globalstar service area.
These constraints, and the service limitations, are described in Section 2.
The MCM-4M provides the ability to establish up to four concurrent satellite connections each
providing 7.2 Kbps of raw symmetrical bandwidth. The MCM-4M provides the combined bandwidth
to the user via a single standard Ethernet connection. The MCM-4M is a full duplex device and can be
configured to allow other data terminals to initiate a data communications connection. For this
purpose, any of the four SDMs may be configured to receive an incoming asynchronous data call from
a PSTN modem. The MCM-4M unit can be connected to up to 3 additional MCM-4M units to
provide the combined bandwidth of up to sixteen concurrent satellite connections.
The MCM-4M requires connection to an Antenna Assembly to be mounted on an external surface.
The MCM-4M contains an Multi-Channel Processor board and four Q
UALCOMM
GSP-1620 Satellite
Data Modems (SDM). The MCM-4M also includes an Ethernet 10 Base-T port, power supplies,
converters, and management functions.