MITSUBISHI ELECTRONICS AMERICA, INC.
ST200 Series Technical Support Manual
18
January 2000
processing techniques also minimize fading effects to a level that outperforms analog cellular
and standard two-way radio systems.
The mean time between failures for the land mobile and fixed site MTs is greater than 5200
hours of continuous use—actual performance may exceed this design value.
:
WARNING
: MT operation may interfere with inadequately protected medical devices,
including pacemakers. Consult a physician or the manufacturer of the medical device
with any questions.
Changes or modifications to the equipment that Mitsubishi Electronics does not expressly
approve can void the authority to operate equipment within commercial and residential
buildings.
5.2 Signaling and Communications Channels
All Mitsubishi MTs access the MSAT network through six different special “channels”. The
following table defines these channels:
Channel
From
To
Purpose
Pilot Signal
CGS
MT
Reference signal for acquisition
GC-S Channel
CGS
MT
System status, call indication, commands
MET-ST Channel
MT
CGS
Responses to CGS commands
MET-SR Channel
MT
CGS
Call setup and other requests
FES-C Channel
CGS
MT
Communications, in-band signaling
MET-C Channel
MT
CGS
Communications, in-band signaling
5.2.1 Pilot Signal
The MSAT satellite continuously transmits an L-band pilot signal in each of five regional
coverage beams. The MT’s pilot signal strength (initially displayed on the handset) serves as a
reference for locating the satellite before initiating the GC-S acquisition process. The pilot
signal itself does not, however, carry any information.
5.2.2 GC-S Channel
The Group Controller-Signaling (GC-S) channels provide network status information, incoming
call indications, and control messages from the CGS to the MT. The MSAT network can
accommodate up to 16 GC-S channels per beam, per control group (see section 2.2). An MT
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