Users Manual Part 2

Precise UTC Time Mode : YES
TETRA Slot : H6121 M49 F15 S4
Synchronized : YES
The following fields are of particular relevance during fault diagnosis:
• Site Reference Operating OK
YES: This indicates that the site reference is providing timing services to the Site Controller.
NO: The site reference is not operating, therefore the MTS cannot provide any service. Examining
the state of items below indicates the reason for this condition.
• 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 is not operational. This is a normal
transitory state.
Site Reference State = MAINTAIN PHASE LOCK: This is a normal operational mode of the site
reference. The MTS is 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 is 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 enters this state where the
site reference calibration data is 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 cannot 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 State = RECOVER PHASE: This state is a normal operational mode. This state
indicates that MTS has acquired signal from GPS and found out that the reference GPS clock is not
aligned with the MTS clock. In this state the MTS tries to align both phase and frequency of internal
clock to the GPS reference clock. The recover phase can take long time, depending on how long
MTS had been working without the GPS signal.
• Site Reference Configuration
Site Reference Configuration = ASC or FNC: This is the installation-selected configuration of the
site reference subsystem. See GPS Site Reference Operation Modes on page 135 for details.
• Site Reference 1 PPS Input Status
6802800U74-AP
Chapter 13: MTS Troubleshooting
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