AT&T 76450 - Manual (Page 14)

Common Systems Connection Standards AT&T Services, Inc
Date: June 2013
ATT-TP-76450, Issue 15
Copyright © 2013, AT&T . All Rights Reserved.
Page 14
3.2 Non-Standard Synchronization Requirements
Some DUCs deployed in cellular base station applications, and some DUCs used for Radio
Node Controller applications use DUC specific timing sources to supply precision frequency
references, Time of Day references, and in some cases a geo-location reference. These timing
sources are not compliant to North American standards for a PRS or TSG, and the interfaces
typically are not compatible with connection to a BITS system. In some cases, a DUC specific
GPS antenna and receiver system are required to support the DUC operation.
3.3 IEEE-1588v2 Precision Time Protocol
Some DUCs deployed in the Outside Plant remote terminal access environment, and some
DUCs deployed in cellular base station applications may use IEEE-1588v2 Precision Time
Protocol (PTP) as a timing solution for sync over Ethernet. Next Generation TSGs are now
available that can deliver PTP from Grand Master server modules housed in a TSG shelf in a
CO or MTSO.
3.4 Network Time Protocol
Network Time Protocol (NTP) has been in use for many years as a means to set time-of-day
clocks in network equipment, computers, routers, etc. More recently, NTP has been used to
deliver a frequency reference to U-verse set top boxes and some wireless base stations. Next
Generation TSGs are now available that can deliver NTP from Stratum 1 server modules
housed in a TSG shelf in a CO or MTSO. In some cases, these servers may by used to deliver
NTP to a DUC.