ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 1
Deutsche Telekom @ITSF2014 Synchronization Network Migration with focus on coherent network Primary Reference Time Clocks (cnPRTC)
Helmut Imlau, 4.11.2014
Synchronization Network Migration with focus on cnPRTC Agenda
ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom
PRTC = Primary Reference Time Clock (ITU-T), cnPRTC = coherent network PRTC (DT), PRTCe = PRTClock ensemble (DT)
4.
The coherent network PRTC idea.
PRTC ensemble measurement results
2 4.11.2014 2 4.11.2014
Synchronization Network Migration
Steps
From “frequency only” synchronization network to a coherent frequency and phase synchroni-zation network.
PRTC ensemble types
Synchronization Network Migration with focus on cnPRTC Migration steps GREEN: FREQUENCY, BLUE: FREQUENCY/PHASE/TIME, RED SHADOW: UTC TRACEABLE
Basis
SSU
#n
#1
eNB
G.812 Type I
G.8262 EECv2
G.811 1x10-11
Frequency
Frequency only
PRC
1GEopt.
G.8262 EECv2
G.8262 EECv2
G.8262 EECv2
Sync Trans-port
3 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
Basis:
Existing frequency synchronization network Using SyncE and SDH For base station synchronization in FDD mode (Frequency Division Duplex)
Components: PRC Primary Reference Clocks SSU Synchronization Supply Units EEC/SEC Ethernet and SDH Equipment Clocks
It consists of backbone network and aggregation network with a SSU’s between both
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Synchronization Network Migration with focus on cnPRTC Migration steps GREEN: FREQUENCY, BLUE: FREQUENCY/PHASE/TIME, RED SHADOW: UTC TRACEABLE
Basis
SSU
#n
#1
eNB
G.812 Type I
G.8262 EECv2
G.811 1x10-11
Frequency
Frequency only
PRC
1GEopt.
G.8262 EECv2
G.8262 EECv2
G.8262 EECv2
Sync Trans-port
STEP 1
Sync Trans-port
#1
eNB
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2 #n
G.8273.2 T-TSC+EECv2
+ UTC-P @#n
PRC
1GEopt.
G.811 1x10-11
Frequency
G.8273.2 T-BC+EECv2
GNSS UTC
G.8262 EECv2
4 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
SSU/PRTC
1st migration step:
UTC traceable phase synchronization at aggregation level for base station synchronization
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Needed for
mobile TDD (Time Division Duplex) or
LTE-Advanced features like CoMP Joint Processing or
eICIC (enhanced Inter-Cell Interference Cancellation) e. g. for HetNet
Synchronization Network Migration with focus on cnPRTC Migration steps GREEN: FREQUENCY, BLUE: FREQUENCY/PHASE/TIME, RED SHADOW: UTC TRACEABLE
Basis
SSU
#n
#1
eNB
G.812 Type I
G.8262 EECv2
G.811 1x10-11
Frequency
Frequency only
PRC
1GEopt.
G.8262 EECv2
G.8262 EECv2
G.8262 EECv2
Sync Trans-port
STEP 1
Sync Trans-port
#1
eNB
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2 #n
G.8273.2 T-TSC+EECv2
+ UTC-P @#n
PRC
1GEopt.
G.811 1x10-11
Frequency
G.8273.2 T-BC+EECv2
GNSS UTC
G.8262 EECv2
5 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
STEP 1.5
Sync Trans-port
#1
eNB
G.8272 UTC Frequency
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2
GNSS UTC
#n
G.8273.2 T-BC+EECv2
G.8273.2 T-TSC+EECv2
+ UTC-F @TOP
GNSS UTC
PRTC
1GEopt.
G.8262 EECv2
SSU/PRTC SSU/PRTC
Intermediate step (1.5):
To make the frequency synchronization network UTC traceable
Preparation for STEP 2
Requirement for HetNet Over-The-Air (OTA) synchronization approach
To improve time holdover based on frequency
Synchronization Network Migration with focus on cnPRTC Migration steps
GREEN: FREQUENCY, BLUE: FREQUENCY/PHASE/TIME, RED SHADOW: UTC TRACEABLE
Basis
SSU
#n
#1
eNB
G.812 Type I
G.8262 EECv2
G.811 1x10-11
Frequency
Frequency only
PRC
1GEopt.
G.8262 EECv2
G.8262 EECv2
G.8262 EECv2
Sync Trans-port
STEP 1,5
Sync Trans-port
#1
eNB
G.8272 UTC Frequency
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2
GNSS UTC
#n
G.8273.2 T-BC+EECv2
G.8273.2 T-TSC+EECv2
+ UTC-F @TOP
GNSS UTC
PRTC
1GEopt.
G.8262 EECv2
STEP 1
Sync Trans-port
#1
eNB
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2 #n
G.8273.2 T-TSC+EECv2
+ UTC-P @#n
PRC
1GEopt.
G.811 1x10-11
Frequency
G.8273.2 T-BC+EECv2
GNSS UTC
G.8262 EECv2
6 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
SSU/PRTC
STEP 2
Sync Trans-port
#1
eNB
G.8272 UTC Frequency +Phase
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2
GNSS UTC
#n
PRTC
G.8273.2 T-BC+EECv2
G.8273.2 T-TSC+EECv2
+ UTC-P @TOP
GNSS UTC
1GEopt.
G.8273.2 T-BC +G.8262 EECv2
SSU/PRTC SSU/PRTC
2nd migration step:
Coherent frequency and phase synchronization for the entire network
Provides uniform UTC traceable quality at CORE level
To make synchronization stable and secure
Optional synergy with other applications like time for smart metering or other via NTP or PTP
Base station level n*10.000 offices
Aggregation Level 1.000 offices
CORE Level 10 offices
STEP 2
Sync Trans-port
#1
eNB
G.8272 UTC Frequency +Phase
G.8272/G.812 (G.8273.4)
G.8273.2 T-BC+EECv2
GNSS UTC
#n
PRTC
G.8273.2 T-BC+EECv2
G.8273.2 T-TSC+EECv2
GNSS UTC
1GEopt.
G.8273.2 T-BC +G.8262 EECv2
SSU/PRTC
+ UTC-P @TOP
Synchronization Network Migration with focus on cnPRTC The coherent network PRTC idea.
7 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
1000
CORE: 10
n*10.000
DT Network View
DT Network view
next page
Synchronization Network Migration with focus on cnPRTC The coherent network PRTC (cnPRTC) idea.
8 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
BIPM Nat. UTC Lab, e. g. PTB
CO900
Network View: All CORE location with coherent network PRTC functions
PTP phase sync links
Clock combiner with adequate calculation and steering algorithm to generate frequency, phase and time
GNSS (e. g. GPS+Galileo) for time, phase , frequency
1 or 2 Cesium (G.811+) for stability, to eliminate GNSS noise
PTP phase links providing time, phase and frequency from and to neighborhood CORE locations
For PTP links: GNSS based asymmetry compensation used
Optional: UTC/BIPM monitor system using UTC(DTAG)
cnPRTC function consists of:
GNSS
local Cs1
local Cs2 Frequency (10MHz)
Phase (1pps)
ToD information
PTP link S1 PTP link S2
PTP link S3
S
S
S
M
PTP link M1 PTP link M2 PTP link M3 M
M
S=PTP Slave M=PTP Master
Clock combiner
Input Output
BIPM = Bureau International des Poids et Measures (Paris)
Synchronization Network Migration with focus on cnPRTC The coherent network PRTC (cnPRTC) idea.
9 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
Uniform UTC traceable network sync quality @ CORE level as basis for all services with frequency, phase and/or ToD supply
Better than PRTC G.8272 per design: max|TE| <30ns instead of <100ns, no noise impact from GNSS
Failure tolerance: After initial synchronization fully GNSS independent, if needed Jamming, spoofing and GNSS shutdown would not be a risk anymore (Definition of the second is based on Cs)
Performance Management: Monitored acc. to BIPM procedures with UTC(DTAG) may be combined with optical fiber based UTC lab connections
cnPRTC advantage:
2 GNSS or
BIPM reg. UTC lab
OCXO Rb
CSAC..
1 or 2 Cs
G.811+
3* PTP
coherent network
PRTC ensemble (cnPRTCe)
G.82 72.y?
NEW: Will be proposed for ITU-T to be specified
2
Synchronization Network Migration with focus on cnPRTC PRTC ensemble types
10 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
Type
Available Time & Timing Sources
Function acc. to ITU-T SG15 Q13 Need-
ed for mi-gra-tion step ….
Time scale gene- ration
Stable frequency generation
Time trans-
fer from other PRTC's
Recommendation
Work status and ongoing activities
Name No.
Internoscil-lator
External oscil-
lator(s)
Basis
GNSS or BIPM reg. UTC lab
OCXO Rb
CSAC..
Primary Reference Time Clock (PRTC)
G.82 72
10/2012: Published for phase/time, NEW: Next version planned for 12/2014: For phase/time and frequency
1.5
1
GNSS or BIPM reg. UTC lab
OCXO Rb
CSAC..
1 or 2 Cs
G.811+
Primary Reference Time Clock
ensemble (PRTCe)?
G.82 72.x
NEW: New study item. From DT contributions WD36+37 (09-2014): Successfully tested, result within ±30ns
1.5
3 GNSS OCXO
Rb CSAC..
1*
PTP
APSC (Assisted Partial Timing Support Clock)
G.82 73.4
Ongoing, planned for consent 12-2014 1
1.5 2
+
+
Synchronization Network Migration with focus on cnPRTC Acknowledgment
11 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014 11 4.11.2014
Thank you very much for the good cooperation during of a PRTC ensemble prequalification versus UTC(PTB) locally in Braunschweig
Dr. Andreas Bauch *) Dr. Dirk Piester
Physikalisch-Technische Bundesanstalt Braunschweig Time and Frequency Department, Time Dissemination Working Group
Tasks of PTB:
Operation of an atomic clock ensemble, Generation of UTC(PTB) and legal time for Germany, Time transfer using TWSTFT and GPS, Dissemination of legal time (DCF77, telephone service, ntp) *) Head of Time Dissemination Working Group
Acknowledgment
Synchronization Network Migration with focus on cnPRTC
12 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
0001/0002: Clock combiner output: 1pps and 10MHz
cnPRTC (local system) measurement results as TE/TIE
0004: 10MHz Cs 3 output
0003: 10MHz Cs 8 output
0001/0002: Clock ensemble output:
1pps and 10MHz
Synchronization Network Migration with focus on cnPRTC
13 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
cnPRTC (local system) measurement results as MTIE
MTIE(160days)
= 60ns
20 Msec
1 sec
3 nsec
100 nsec (PRTC limit)
1000 nsec
1 Msec (11,6 days)
4.
The coherent network PRTC idea.
PRTCe measurement results
Synchronization Network Migration
Step Options
From “frequency only” synchronization network to a coherent frequency and phase synchroni-zation network.
Synchronization Network Migration with focus on cnPRTC
14 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
PRTC ensemble types
Synchronization Network Migration with focus on cnPRTC Abbreviations
15 ITSF 2014: Synchronization Network Migration Steps with focus on PRTC - Helmut Imlau, Deutsche Telekom 4.11.2014
1 PPS 1Pulse per Second APSC Assisted Partial Timing Support Clock BIPM Bureau International des Poids et Measures (Paris) CoMP Coordinated Multi-Processing Transmission and Receiving CSAC Chip-Scale atomic Clock cnTRTC coherent network PRTC Cs Cesium atomic clock DCF77 Radio transmitter station identification code, given by ITU, “D” for Deutschland (long-wave transmitter for dissemination of legal time Germany, 77,5MHz) eICIC enhanced Inter-Cell Interference Cancellation eNB envolved NodeB (LTE basestation) EEC Ethernet Equipment Clock FDD Frequency Division Duplex GNSS Global Navigation Satellite System GPS Global Positioning System HetNet Heterogeneous network (macro – small cell overlap) ITU International Telecommunication Union ITU-T ITU - Telecommunication Standardization Sector MTIE Maximum Time Interval Error NTP Network Time Protocol OCXO Oven-Controlled Crystal Oscillator OTA Over-The-Air (Synchronization) PRC Primary Reference Clock PRTC Primary Reference Time Clock PRTCe PRTC ensemble PTB Physikalisch-Technische Bundesanstalt Braunschweig PTP Precision Time Protocol Q Question (ITU-T, Q13 = Timing & Synchronization) Rb Rubidium atomic clock SDH Synchronous Digital Hierarchy SG Study Group (ITU-T) SSU Synchronization Supply Unit SyncE Ethernet Physical Layer Synchronization TDD Time Division Duplex TWSTFT Two-Way Satellite Time and Frequency Transfer UTC Universal Time Coordinated UTC(PTB) Universal Time Coordinated (Physikalisch-Technische Bundesanstalt Braunschweig) UTC(DTAG) Universal Time Coordinated (Deutsche Telekom AG) UTC lab BIPM registered official time lab contributing UTC WD Work Draft (acc. to ITU-T rules)