User's Manual Part 2

CSA System Time – GPS & HSO/MSO Verification – continued

6-44 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU MAY 2004

PRELIMINARY

High Stability Oscillator /

Medium Stability Oscillator

(HSO/MSO)

General

CSA and HSO/MSO

The CSA utilizes timing signals provided by either an HSO or MSO to

maintain BTS synchronization during the absence of valid GPS timing

information. WHen a GPS timing signal is available the CSA is

responsible for calibration of the HSO or MSO clock to maximize the

backup timing interval. A minimum period of 24 hours of operation with

a valid GPS reference is required to fully calibrate the HSO backup

reference such that a 24 hour backup interval may be provided.

HSO

The HSO is a free–running backup oscillator that is capable of providing

a minimum backup interval of 24 hours.

MSO

The MSO is a free–running backup oscillator that is capable of providing

a minimum backup interval of 8 hours.

NOTE

Allow the base site and test equipment to warm up for 60

minutes after any interruption in oscillator power. CSA 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.