Fibre Characterisation and FTTx New challenges

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1 Fibre Characterisation and FTTx New challenges Broadband Technology Event Rotterdam, November 10th, 2009 Nicolas CARLIER France & Benelux RSM

2 What is Fiber Characterisation when is it used, what is its worth? Regardless if the services are to be deployed on a new build or existing fiber network, a series of measurements need to be performed to certify the link is appropriate for use. The suite of measurements performed are known as Fiber Characterisation. The specific requirements are identified by ITU-T SG15 ref: G

3 What is Fiber Characterisation when is it used, what is its worth? Higher speed services are not a case of plug and play. The physical layer (fiber) needs to be properly characterised to ensure the services can be deployed. Examples: FTTH, 10G, 10GbE, DWDM, 40G, 100G Adopting an appropriate FC strategy is mission critical to the operator. Failure to do so will mean an inability to deploy the service in a timely manner costing $$$ and competitive advantage. 3

4 What is Fiber Characterisation when is it used, what is its worth? The scope of these measurements may differ, but according to G These measurements are needed to verify if the network or link is capable of delivering the required service Their purpose is to ensure the network has been: 1) installed correctly with good splicing, handling and cleanliness 2) the fibre has the ability to carry high bandwidth services. If these parameters are not met there can be a catastrophic effect on the transmission speed, resulting in delays of operation and the inability to not use high speeds. Therefore, Fibre Characterisation becomes vitally important. 4

and scratch-free) essential for low loss and future issues on the

5 What Does G Recommend? The basic set of Tier 1 tests consist of: Connector end faces (clean and scratch-free) essential for low loss and future issues on the network Bidirectional OTDR quality of the splicing, handling and cleanliness of the fibre installation. Bidirectional OLTS (sometimes called ILM) required to perform a final functional check that the power budget is within specification/operating limits 5

prone to operator error Accuracy and good practice are key to

6 ILM/ORL solution An ILM/ORL set certifies whether the overall link will satisfy design criteria Highly time consuming and prone to operator error Accuracy and good practice are key to reliable data collection automation is key Source Power meter 6

OTDR solution An OTDR is used to confirm that the

should therefore allow the system budget to be in

7 OTDR solution An OTDR is used to confirm that the fibers, splicing and connectors in a system are within the specified tolerance. This shows a good quality installation and this should therefore allow the system budget to be in specification. FTB-200 F2 OLT Total Link Loss & Reflectance - OTDR F1 No transmission ONT 7

8 FTTx specificities Broadband Technology Event Rotterdam, November 10th, 2009

9 Typical FTTx Topologies Examining the Differences Point to point PON Splitter Active Ethernet Switch 9

10 New architecture trend: MDU (Multi Dwelling Unit) Vertical/Medium/ High rise MDU Horizontal/ Garden style MDU 11

Closely spaced events: Typically 3 spans from FDH between 50m and 500m

11 FTTx Specificities 1. Multiple connections (connectors or splices) 2. Splitters, single or double stage up to 1x64 (up to 20dB loss) 3. Closely spaced events: Typically 3 spans from FDH between 50m and 500m 4. Mixture of standard SMF- 28 and bend insensitive fibers 5. Macrobends 12

12 Multiple connections - Splitters Drop terminal Splitter Patch panel C.O. Patch panel End of link Splice tray Splice tray C.O. OLT FTB

13 Closely spaced events C.O. Patch panel FDH Splice tray Fiber Collector Patch panel FTD Drop terminal C.O. OLT Few hundred meters to several km ~ 100m ~ 10m ~ 10m ONT OTDR 14

14 SMF-28 and Bend insensitive fibers The only way to qualify those splices is to measure in both directions and average 15

15 Macrobends 16

16 Main Tech Pains with standard OTDR Can t differentiate closely spaced events --> standard OTDRs lack of resolution at higher pulses Can t measure a splitter loss with accuracy --> standard OTDRs lack of dynamic range at lower pulses Can t locate problems on F1 fiber passed the splitter --> standard OTDRs lack the resolution at higher pulses = long DZ Can t troubleshoot one customer without disconnecting from the network --> Live fiber testing requires a filtered and out-of-band OTDR CONCLUSION: standard OTDRs are not adapted for FTTx characterization 17

17 A picture worth a thousand tests 1:32 splitter, 275ns, 15 sec averaging time 55 meters dead zone High dynamic range OTDR FTTx OTDR Standard OTDR 18

Measurements in Active Networks OTDR tests require no transmission signal on the fibre (dark fibre) Max tx signal power still allowing OTDR acquisition: - 45 dbm Max signal before damaging APD: - 20

18 Measurements in Active Networks OTDR tests require no transmission signal on the fibre (dark fibre) Max tx signal power still allowing OTDR acquisition: - 45 dbm Max signal before damaging APD: - 20 dbm => That section of the PON has to be turned off, affecting other customers OTDR with out of band filtered port allows testing of branches without disturbing other customers. **ITU-T Recommendation L66: nm Maintenance band nm Monitoring wavelength 19

19 FTTH Service-Activation Active Ethernet Switching At the subscriber s premises 1. Install and power up ONT 2. Connect/splice drop cable 3. Measure optical signal F1 Ethernet Switch F2 Continuous wave (CW) signal PON (Passive) IPTV Burst signal RF 20

Cleaning Connectors Cleaning is one of the most neglected operations but it is the most

dirty connectors when high power signal is turned on.

This must be done at LT,NT, ONT, splitter and ODF.

20 Cleaning Connectors Cleaning is one of the most neglected operations but it is the most important one 75% of network problems are related to connectors Permanent damage can occur on dirty connectors when high power signal is turned on. Remember also to clean the connector which you connect to. This must be done at LT,NT, ONT, splitter and ODF. All connectors MUST be clean before they are inserted. ICI!!!!!!! Clean connector Dirty connector Permanantly damaged In addition dirty connectors give high reflectance high reflectance can «kill» an OTDR trace! 21

21 Inspecting connectors Using a video inspection probe is the safest way to inspect connectors 22

22 SUMMARY : What to test, when? Construction check cables/fibers check splices and connectors check continuity inspect connectors Activation inspect connectors check power level Troubleshooting inspect connectors check power level locate default OTDR / OLTS OTDR VFL Inspection Probe Inspection Probe Power meter (standard or PON) Inspection Probe PON Power Meter OTDR / Filtered OTDR 23

23 EXFO s solutions for FTTx Mainframe FTB-200 FTTx OTDR FTB-7300E OLTS FTB-3930 FTTx/Access OTDR AXS-100/AXS-110 Inspection probe : Option for FOT-930, FTB-200, AXS-100/AXS-110, or available as stand alone unit OLTS FOT-930 MaxTester Loss, length, ORL Powemeter PPM-350C 24

24 Questions? Meet us at CN ROOD s booth

Accelerating NBN fiber testing. Tom Ronan Marketing Lead Fiber Optics Melbourne

Accelerating NBN fiber testing and workforce Performance. Tom Ronan Marketing Lead Fiber Optics Melbourne Agenda Network Elements and Parameters Distributed Fiber Network (DFN) Construction Network Activation