Sync Challenges In Telecom Networks · Sync Challenges In Telecom Networks James Armstrong EVP/GM,...
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Sync Challenges In Telecom Networks James Armstrong EVP/GM, Symmetricom, Inc. November 2, 2010
Transcript of Sync Challenges In Telecom Networks · Sync Challenges In Telecom Networks James Armstrong EVP/GM,...
Sync Challenges In Telecom Networks
James Armstrong
EVP/GM, Symmetricom, Inc.
November 2, 2010
PAGE 2© COPYRIGHT SYMMETRICOM (2010)
Transitions In Telecom Networks
Infrastructure Premise Femtocells
TDM EthernetCarrier Ethernet,
Mobile Backhaul
GPS GNSSGalileo, Beidou,
GLONASS,…
FrequencyOnly
Frequency + Time
WiMAX, TD-SCDMA,
TD-LTE, LTE-MBMS,..
PAGE 3© COPYRIGHT SYMMETRICOM (2010)
Wireless
BTS
SSU
TDM
Access
(CES/PWE)
TDM
TDM
TDM
TDM
TDM Ethernet
PAGE 4© COPYRIGHT SYMMETRICOM (2010)
Wireless
Base StationEthernet
SSU
Access
(CES/PWE)
Ethernet
Ethernet
Ethernet
Ethernet
33 TDM Ethernet
PAGE 5© COPYRIGHT SYMMETRICOM (2010)
Wireless
Base Station
Residential
Gateway
Femto
IEEE 1588/NTP
IEEE 1588
SyncE
IEEE 1588SyncE
SSU
TDM
Access
(CES/PWE)
Grand Master /NTP Server
IEEE 1588
TDM Ethernet
PTP / IEEE 1588
SyncE
NTP
NTP
Protocols Have Now Been Ratified SyncE – standardization completed
10/2008
IEEE 1588 v2 – March, 2008
PAGE 6© COPYRIGHT SYMMETRICOM (2010)
Application Frequency Time
CDMA2000 (includes femtocells)
50 ppb<3µs when locked to GPSMust Meet: <10µs
GSM/UMTS/ WCDMA 50 ppb N/A
UMTS microcells 100 ppb N/A
UMTS femtocells 250 ppb N/A
TD-SCDMA 50 ppb 3µs inter-cell phase difference
WiMAX (TDD) (includes femtocells)
2 ppm absolute, ~50 ppb between base stations
Typically1 -8 µs
LTE (FDD) 50 ppb N/A
LTE (TDD) 50 ppb 2.5 µs inter-cell phase difference
LTE MBMS 50 ppb 5µs inter-cell phase difference
LTE MIMO 50 ppb500 ns (0.5 µs) inter-cell phase difference
FrequencyOnly
Frequency + Time
> Holdover, practical requirement:
Customer Experience
Revenue Protection
Regulatory – E911
> High End Oscillator (Rb) needed
> Multiple Technologies Aiding One Another
PAGE 7© COPYRIGHT SYMMETRICOM (2010)
GPS GNSS
Support For Multiple GNSS Required
GNSS Backup Required
GPS
GALILEO GLONASS
BEIDOU
PAGE 8© COPYRIGHT SYMMETRICOM (2010)
Source: Infonetics, March 2010
0
10
20
30
40
50
60
CY07 CY08 CY09 CY10 CY11 CY12 CY13 CY14
Un
its
(M
illi
on
s)
Femtocells
Infrastructure Premise
Combination of
Technologies Required
GNSS
Oscillators
Network Assistance
250 ppb Over DSL or
DOCSIS Required for
Femto Synchronization
PAGE 9© COPYRIGHT SYMMETRICOM (2010)
Meeting The Sync Challenge
Multiple technologies required to aid one another
Holdover is a critical requirement
PAGE 10© COPYRIGHT SYMMETRICOM (2010)
Meeting The 1µsec Challenge
GNSS with PTP Assist
GNSS with Rubidium Holdover
PTP with Rubidium Holdover
GNSS, PTP, Rubidium – You Need 2 Out of 3
PAGE 11© COPYRIGHT SYMMETRICOM (2010)
It Takes Two, Baby (Marvin Gaye)
One can have a dream, baby
Two can make that dream so real
One can talk about bein' in love
Two can say how it really feels
One can wish upon a star
Two can make that wish come true, yeah
One can stand alone in the dark
Two can make the light shine through
It takes two, baby
It takes two, baby
Me and you, just takes two
It takes two, baby
It takes two, baby
To make a dream come true, just takes two
Thank You!!!
www.symmetricom.com
