Motorola DIMETRA MTS 2 Installation, Configuration And Basic Service Manual page 376

Troubleshooting: GPS and Site Reference Faults
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13-10
Site Reference State
Site Reference State = START UP: The Site Controller is starting up and the site reference
has not been fully initialized yet. The site reference and the MTS will not be operational at this
point. This is a normal transitory state.
Site Reference State = ACQUIRE FREQUENCY LOCK: The site reference is in the
process of locking to the reference signal provided by the GPS receiver. This process may take
several minutes. The MTS will not be able to provide any service until this process completes.
Site Reference State = MAINTAIN PHASE LOCK: This is a normal operational mode of
the site reference. The MTS will be synchronized with any other MTS that has attained this
state, this means that type 1 handovers and any other feature that require sites to be fully
synchronized will be available.
Site Reference State = SYNCHRONISED FREE RUN: This is a fallback state which
indicates that the MTS is not tracking sufficient GPS satellites to provide a timing reference
to the site. The MTS is capable of operating with no loss of performance for up to 12 hours
(dependent on configuration). If this condition occurs frequently or persists, the health of the
GPS system should be assessed. See GPS Tracking criteria and GPS Antenna evaluation in
section 4 of this manual
Site Reference State = UNSYNCHRONISED FREE RUN: This is a fallback state for
an ASC configured MTS and the normal operating state for FNC configured MTS. When
configured for ASC, the site will enter this state if adequate GPS tracking is not achieved
before the configured GPS start up timer expires or after the expiry of free run timer if the
site was previously synchronized. The site is capable of operating in this mode for up to 12
months. In this state the MTS is capable of providing all services except those that require
synchronization between adjacent sites, for example, type 1 handovers.
Site Reference State = MAINTAIN FREQUENCY LOCK: If an adequate GPS signal
becomes available whilst operating in UNSYNCHRONISED FREE RUN the MTS will enter
this state where the site reference calibration data will be updated, thus prolonging the amount
of time where service can be maintained.
Site Reference State = DISABLED: The site reference has detected an error and is unable to
provide any service. The MTS will not be able to provide any service whilst the site reference is
in this state. The cause of this state is dependent on the configured operating mode of the MTS:
◦ FNC / ASC: The MTS does not have any calibration data - The MTS needs to be
run initially with GPS before FNC operation without GPS is possible.
This condition may also be due to hardware failure within the Site Controller.
Site Reference Configuration
Site Reference Configuration = ASC or FNC: This is the installation selected configuration
of the site reference subsystem. See
Site Reference 1 PPS Input Status
Site Reference 1 PPS Input Status = OK or NOT OK: This indicates whether a
valid signal is being received by the site reference system.
GPS Operating OK
GPS Operating OK = YES or NO: This indicates whether the GPS receiver is tracking
sufficient satellites to provide a timing reference input to the site reference. This parameter
should be YES for ASC operation. Detailed information on the GPS receiver may be obtained
from the status sri -t and status sri -gps commands. See the following section for details.
"Site Reference Operation Modes"
Chapter 13: MTS Troubleshooting
for details.
6802800U74-N September 2009