In Service Monitoring and Assurance at ITSF 2014
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1) Synchronization assurance is important for mobile backhaul networks to ensure synchronization quality as network conditions can affect timing. 2) In-service monitoring tools are needed to continuously monitor synchronization sources and the network to detect errors early, as using lab equipment for each location is too expensive. 3) Examples of in-service monitoring include monitoring a slave clock against GNSS while it is available, then against the secondary source; and monitoring boundary clocks and the network connecting synchronization sources.
In Service Monitoring and Assurance at ITSF 2014
- 1. Nir Laufer, ITSF 2014, Budapest In Service Monitoring & Assurance
- 2. © 2014 ADVA Optical Networking. All rights reserved. Confidential.2 New Requirement – New Challenges! • Time/Phase requirement for NGN are much more stringent! • Frequency offset accumulate to phase error. • G.8265.1 compliant clock with frequency offset of 16ppb will exceed 1.1usec limits after ~70 seconds... Telecom Profile Requirement Frequency G.8261.1 16ppb Phase G.8271 +/- 1.5/1.1usec
- 3. © 2014 ADVA Optical Networking. All rights reserved. Confidential.3 • Synchronization assurance is a highly relevant feature • Conclusion: Mobile operators want to see such capability with their synchronization delivery solution Operators Survey - Synchronization Assurance Do you rate synchronization service assurance as an important tool for delivering mobile backhaul services? 12% 52% 36% not important mandatory interesting option
- 4. © 2014 ADVA Optical Networking. All rights reserved. Confidential.4 Why „In Service“ Sync Assurance is Needed • Making sure synchronization is working as designed is not trivial task. • Network PDV, asymmetry and environmental conditions can effect the Synchronization quality. • A way to ensure proper synchronization should be integrated into Sync distribution/delivery functions or accompanied by cost effective Sync assurance tools. • Lab test equipment is too expansive for “in service” installation in multiple locations. • Other aspects such as power consumption and OSS/NMS should also be taken into consideration.
- 5. © 2014 ADVA Optical Networking. All rights reserved. Confidential.5 Example 1: Assisted Partial Timing Support • GNSS feeding PRTC as GM primary source • PTP/Sync-E/PTP+Sync-E inputs as secondary source T-GM GNSS PTP Grandmaster Packet-Based Backhaul Network APTS mini-GM Local Base Station GNSS Remote Base Station T-SC T-SC T-SC T-SC BC PTP/Sync-E/PTP+Sync-E
- 6. © 2014 ADVA Optical Networking. All rights reserved. Confidential.6 Example 1: Assisted Partial Timing Support • In case of GNSS failure – the secondary source is becoming active T-GM GNSS PTP Grandmaster Packet-Based Backhaul Network APTS mini-GM Local Base Station GNSS Remote Base Station T-SC T-SC T-SC T-SC BC PTP/Sync-E/PTP+Sync-E How can the operator validate the quality of the secondary source prior to GNSS outage?
- 7. © 2014 ADVA Optical Networking. All rights reserved. Confidential.7 Example 1: Assisted Partial Timing Support APTSC PRTC GNSS Slave TE/TIE 1PPS 1PPS MTIE TIE TE TDEV Total TE dTE cTE KPI #1 KPI #2 KPI #3 KPI #4 KPI #5 PDV/ Asymmetry Metrics PTP Packets KPI #6 PTP TE/TIE Sync-E EEC CLK • Use GNSS while available to monitor and assure the secondary sources
- 8. © 2014 ADVA Optical Networking. All rights reserved. Confidential.8 APTS KPIs and SLA • PRTC Vs. PTP Slave recovered clock (PTP Input) • Total/Constant/Dynamic Time Error (TE) Vs predefined threshold • MTIE Vs predefined mask • Network asymmetry and PDV • PRTC Vs. Sync-E • MTIE Vs predefined mask • The results and failure alarms should be collected by the NMS • Can help early in detection of error in primary and secondary sources
- 9. © 2014 ADVA Optical Networking. All rights reserved. Confidential.9 Example 2: Time and Phase Delivery G.8271.1 Network Limits • Maximum absolute time error network limit applicable at the reference point C: max |TE| ≤ 1100 ns , MTIE under G.8271.1 Dynamic Time Error network limit |TE|<1100nsec MTIE τ (s) 660ns 360ns 250ns 1µs 100ns 0.01 0.0625 1 2.2 10 100 275 1000 100000.1
- 10. © 2014 ADVA Optical Networking. All rights reserved. Confidential.10 Example 2: G.8271.1 Network Limits Deployment Case 1 • Option A - Via 1PPS Physical Signal • Option B - from the two-way PTP flow via a Passive PTP Probe GPS Antenna Delay compensation (X) GPS Antenna Tcombined_error ≈ (TM2 – T1 – T4 + TM3)/2 Sync Probe Sync Probe
- 11. © 2014 ADVA Optical Networking. All rights reserved. Confidential.11 Example 2: G.8271.1 Network Limits Deployment Case 1 – Option C • Option C- From the two-way PTP flow via an Active PTP Probe Tcombined_error ≈ (T2 – T1 – T4 + T3)/2 GPS Antenna Sync Probe
- 12. © 2014 ADVA Optical Networking. All rights reserved. Confidential.12 Example 3: Frequency Delivery G.8261.1 Network Limit HMR1 • FPP: For any window interval of 200 seconds at least 1% of transmitted timing packets will be received within a fixed cluster, starting at the observed floor delay, and having a range of 150 µs (G.8260 floor delay packet population). 200s 150usec
- 13. Probing and Monitoring Slave Clock
- 14. © 2014 ADVA Optical Networking. All rights reserved. Confidential.14 Probing Slave Clock RNCRNC Slave Clock Boundary Clock Boundary Clock Transparent Clock PRC/PRTC Grand Master
- 15. © 2014 ADVA Optical Networking. All rights reserved. Confidential.15 Probing Third Party Slave Clock • Slave 1PPS and clock outputs can be monitored Vs. GPS/external reference • Time Error , TIE and MTIE can be calculated and compared against target performance masks / metrics GPS Slave Clock (DUT) T1 T4 T3 10MHz/BITS/Sync-E T1 T4 T3 1PPS T-GM Network CLK TIE & 1PPS Time Error CLK & 1 PPS MTIE Sync Probe
- 16. © 2014 ADVA Optical Networking. All rights reserved. Confidential.16 T1 T4 Probing an Third Party Slave Clock • Probing the Slave Clock – Passive Probing • A Sync Probe is placed at a calibrated distance from the Slave Clock (system under test) • The Sync Probe functions as passive PTP probe (fiber tapping or mirroring switch) • The Sync Probe measure packet TE/TIE/MTIE of the tapped Slave port against a reference measurement timing signal GPS Slave Clock (DUT) T3 T1 T4 T3 T3 Packet MTIE Packet Time ErrorT-GM Network Sync Probe
- 17. © 2014 ADVA Optical Networking. All rights reserved. Confidential.17 Slave Clock Self Monitoring • The probing functions are integrated into the slave clock which deliver clock to the end application • Internal 1PPS and clock recovered from PTP can be self monitored Vs. GPS/external reference as well as T3 generated by Slave Clock GPS T1 T4 T3 10MHz/BITS/Sync-E T1 T4 1PPS T-GM Network CLK TIE and 1PPS Time Error CLK and 1PPS MTIE Sync Probe + Slave Clock
- 18. Probing and Monitoring Boundary Clock
- 19. © 2014 ADVA Optical Networking. All rights reserved. Confidential.19 Probing Boundary Clock RNCRNC Slave Clock Boundary Clock Boundary Clock Transparent Clock PRC/PRTC Grand Master
- 20. © 2014 ADVA Optical Networking. All rights reserved. Confidential.20 Probing Third Party Boundary Clock • A Sync Probe is used for assurance of third party Boundary Clock • Boundary Clock 1PPS and clock outputs can be monitored Vs. GPS reference GPS Boundary Clock (DUT) Slave Clock T1 T4 T3 10MHz/BITS/Sync-E T1 T4 T3 CLK TIE & 1PPS Time Error CLK & 1PPS MTIE 1PPS T-GM Sync Probe
- 21. © 2014 ADVA Optical Networking. All rights reserved. Confidential.21 Boundary Clock Self Monitoring • The probing functions are integrated into the Boundary Clock • The internal BC 1PPS and clock recovered from PTP can be self monitored simultaneously GPS Slave Clock T1 T4 T3 10MHz/BITS/Sync-E T1 T4 T3 1PPS T-GM CLK TIE and 1PPS Time Error CLK and 1PPS MTIE Sync Probe + Boundary Clock
- 22. © 2014 ADVA Optical Networking. All rights reserved. Confidential.22 Probing an Third Party Boundary Clock • Probing the Master side of a Boundary Clock – Active Probing • The Sync Probe is placed at a calibrated distance from the Master port of an Third Party Boundary Clock (system under test) • The Sync Probe functions as active probe GPS Boundary Clock (DUT) Slave Clock T1 T4 T3 T1 T4 T3 T1 T4 CLK ,1PPS MTIE & Packet MTIE CLK TIE ,1PPS TE & Packet TE T3 T-GM 1PPS 10MHz/BITS/Sync-E Active Probing of PTP timing signal can combined with probing of 1PPS /CLK physical signals Sync Probe
- 23. © 2014 ADVA Optical Networking. All rights reserved. Confidential.23 Self Monitoring Network - G.8275.1 • G.8275.1 architecture cab be based on very long chains of BC (i.e. 20 hops)- how can the operator find the point of failure? • No GPS or external reference is needed! • Each BC in the chain can compare next hope recovered clock Vs. his own recovered clock. This is done by compering T3 received form next hop against his own recovered clock which is used as reference. T-GM GNSS PTP Grandmaster & Sync-E PTP Slave Clock Slave BC & Sync-E BC & Sync-E BC & Sync-E BC & Sync-E BC & Sync-E BC & Sync-E 4G Base Station / Small Cell 16ppb & +/-1.1us Ethernet Multicast T3 T3 T3T3 T3 T3
- 24. Probing and Monitoring the Network
- 25. © 2014 ADVA Optical Networking. All rights reserved. Confidential.25 Probing the Network RNCRNC Slave Clock Boundary Clock Boundary Clock Network PRC/PRTC Grand Master
- 26. © 2014 ADVA Optical Networking. All rights reserved. Confidential.26 Probing the Network • A Sync Probe can be used for testing the network connecting the master and Slave/BC • Collect statistical information about the network (PDV, packet loss…) and can decide on network usability and KPI • Packet Counters (arrived, lost) • PD (Path Delay) , MPD (Mean Path Delay) ,Asymmetry • Network Usability (i.e. based on G.8261.1 FPP) • Calculate PM statistics (i.e. 15min ,24hours) and TCAs in order to validate Sync SLA performance T-GM BC/SC ?
- 27. © 2014 ADVA Optical Networking. All rights reserved. Confidential.27 PTP Network Active Probe • Active Probe uses the internal Telecom slave packets exchanged • The Sync Probe can probe the network and recover the clock simultaneously PTP network Probe Statistics and Usability Score GPS T1 T4 T3 T1 T4 T-GM Network (DUT) Sync Probe + Slave Clock
- 28. © 2014 ADVA Optical Networking. All rights reserved. Confidential.28 PTP Network Passive Probe • Passive probe tap packet exchanged between master third party slave / boundary clock T1 T4 GPS Slave Clock T3 T1 T4 T3 T-GM Network (DUT) PTP network Probe Statistics and Usability Score Sync Probe
- 29. © 2014 ADVA Optical Networking. All rights reserved. Confidential.29 Simultaneous Testing • Simultaneously probing of the Clock and the Network can help in troubleshooting problems GPS Slave Clock (DUT) T1 T4 T3 T1 T4 CLK ,1PPS MTIE & Packet MTIE CLK TIE ,1PPS TE & Packet TE T3 T-GM 1PPS 10MHz/BITS/Sync-E Network (DUT) PTP network Probe Statistics and Usability Score Sync Probe
- 30. © 2014 ADVA Optical Networking. All rights reserved. Confidential.30 Sync Probing Examples - Live Network • Probing BC 1PPS and PTP output Sync Probe GPS PTP Optical connectivity 1PPS cable GM Network BCPTP Network
- 31. © 2014 ADVA Optical Networking. All rights reserved. Confidential.31 Summary • Time/Phase requirement for NGN are stringent! • In services probing is needed in order to ensure proper synchronization is delivered • Monitoring the accuracy of the Synchronization delivered is possible using Sync Probes which can be used for monitoring the Clocks and/or the Network OSA 5411
- 32. Nlaufer@advaoptical.com Questions? Thank you! IMPORTANT NOTICE The content of this presentation is strictly confidential. ADVA Optical Networking is the exclusive owner or licensee of the content, material, and information in this presentation. Any reproduction, publication or reprint, in whole or in part, is strictly prohibited. The information in this presentation may not be accurate, complete or up to date, and is provided without warranties or representations of any kind, either express or implied. ADVA Optical Networking shall not be responsible for and disclaims any liability for any loss or damages, including without limitation, direct, indirect, incidental, consequential and special damages, alleged to have been caused by or in connection with using and/or relying on the information contained in this presentation. Copyright © for the entire content of this presentation: ADVA Optical Networking.
Editor's Notes
- #5: Synchronization is a service which deliver Frequency/Phase/Time Like other services , ways to monitor , test and analyze the quality of the service are needed Clock Accuracy –Frequency ,phase and time accuracy measurement based on physical signals relative to reference Clock Analysis - Frequency and phase analysis based on packet timing signals measured relative to reference PTP Network Analysis - PTP path monitoring / testing
- #15: I think this slide is good however there are a few questions… (some of these are tricky) If there is an FSP 150 can they all provide SyncJack? If there is an FSP 150 would we also need to provide a SyncProbe? Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?
- #20: I think this slide is good however there are a few questions… (some of these are tricky) If there is an FSP 150 can they all provide SyncJack? If there is an FSP 150 would we also need to provide a SyncProbe? Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?
- #26: I think this slide is good however there are a few questions… (some of these are tricky) If there is an FSP 150 can they all provide SyncJack? If there is an FSP 150 would we also need to provide a SyncProbe? Do we need a SyncProbe at every location in the this cloud or can we skip some nodes (how do we determine this)?