User's Manual
Table Of Contents
- Contents
- Chapter 1 Introduction
- Chapter 2 Preliminary Operations
- Chapter 3 Optimization/Calibration
- Introduction to Optimization and Calibration
- Preparing the LMF
- Overview of Packet BTS files
- LMF Features and Installation Requirements
- LMF File Structure Overview
- LMF Home Directory
- NECF Filename Conventions and Directory Location
- LMF Installation and Update Procedures
- Copy BTS and CBSC CDF (or NECF) Files to the LMF Computer
- Creating a Named HyperTerminal Connection for MMI Communication
- Span Lines - Interface and Isolation
- LMF to BTS Connection
- Using the LMF
- Pinging the Processors
- Download the BTS
- CSM System Time - GPS & LFR/HSO Verification
- Test Equipment Set-up
- Test Set Calibration
- Background
- Calibration Procedures Included
- GPIB Addresses
- Selecting Test Equipment
- Manually Selecting Test Equipment in a Serial Connection Tab
- Automatically Selecting Test Equipment in the Serial Connection Tab
- Calibrating Test Equipment
- Calibrating Cables Overview
- Calibrating Test Cabling using Communications System Analyzer
- Calibrate Test Cabling Using Signal Generator & Spectrum Analyzer
- Setting Cable Loss Values
- Setting TX Coupler Loss Value
- Bay Level Offset Calibration
- Purpose of Bay Level Offset Calibration
- What is BLO Calibration?
- Component Verification During Calibration
- When to Calibrate BLOs
- BLO Calibration Data File
- Test Equipment Setup for RF Path Calibration
- Transmit (TX) Path Calibration Description
- TX Calibration and the LMF
- TX Calibration
- All Cal/Audit and TX Calibration Procedure
- Download BLO Procedure
- Calibration Audit Introduction
- TX Path Audit
- TX Audit Test
- Create CAL File
- RFDS Set-up and Calibration
- Alarms Testing
- Chapter 4 Automated Acceptance Test Procedures
CSM System Time – GPS & LFR/HSO Verification
68P64115A18–1
Mar 2003
1X SC 4812T Lite BTS Optimization/ATP Software Release R2.16.1.x
DRAFT
3-46
Low Frequency Receiver/High Stability Oscillator (LFR/HSO)
General
The CSM and the LFR/HSO – The CSM performs the overall
configuration and status monitoring functions for the LFR/HSO. In the
event of GPS failure, the LFR/HSO is capable of maintaining
synchronization initially established by the GPS reference signal.
LFR – The LFR requires an active external antenna to receive
LORAN–C RF signals. Timing pulses are derived from this signal,
which is synchronized to Universal Time Coordinates (UTC) and GPS
time. The LFR can maintain system time indefinitely after initial GPS
lock.
HSO – The HSO is a high stability 10 MHz oscillator with the necessary
interface to the CSMs. The HSO is typically installed in those
geographical areas not covered by the LORAN–C system. Since the
HSO is a free–standing oscillator, system time can only be maintained
for 24 hours after 24 hours of GPS lock
Upgrades and Expansions: LFR2/HSO2/HSOX
The LFR2 and HSO2 (second generation cards) both can export a timing
signal to other BTS frames located at a site. These secondary frames
require an HSO–expansion (HSOX) module whether the primary frame
has an LFR2 or an HSO2. The HSOX accepts input from the primary
frame and interfaces with the CSM cards in the secondary frames. LFR
and LFR2 use the same source code in source selection (Table 3-19).
HSO, HSO2, and HSOX use the same source code in source selection
(Table 3-19).
NOTE
Allow the base site and test equipment to warm up for 60
minutes after any interruption in oscillator power. CSM card
warm-up allows the oscillator oven temperature and oscillator
frequency to stabilize prior to test. Test equipment warm-up
allows the Rubidium standard time base to stabilize in frequency
before any measurements are made.