Ftth pon training guide part iv
Download as PPTX, PDF0 likes633 views
This document provides guidance on designing and implementing fiber-to-the-home (FTTH) networks using passive optical networks (PON). It discusses choosing between centralized and cascaded splitting approaches. Centralized splitting uses a single splitter located close to the optical line terminal, while cascaded splitting uses multiple splitters in a tree-like structure. The document also covers topics like choosing splitter types, calculating splitting ratios and attenuation budgets, and testing optical power levels. Designing an FTTH network requires considering factors like topology, subscriber density and distance to optimize network performance and cost.
Ftth pon training guide part iv
- 1. FTTH PON TRAINING GUIDE PART IV BY EMMANUEL N ONUZURIKE (CFOT/CFOS/H/I/O/D/S/T)
- 2. DESIGNING AND IMPLEMENTATION OF A TYPICAL FTTH NETWORK How to Design Your FTTH Network Splitting Level and Ratio
- 3. HOW TO DESIGN A SIMPLE FTTH SPLITTING LEVEL RATIO In Passive Optical Network (PON), optical splitters play an important role in Fiber to the Home (FTTH) networks by allowing a single PON interface to be shared among many subscribers. Optical Splitters are installed in each optical network between the PON Optical Line Terminal (OLT) and the Optical Network Terminals (ONTs) that the OLT serves. During the deployment of fiber to the home passive optical network, usually, we will face some physical access network design problems. This article may help you solve FTTH splitting lever and ratio design problems
- 4. HOW TO DESIGN A SIMPLE FTTH SPLITTING LEVEL RATIO
- 5. CHOOSE PLC SPLITTER OR FBT SPLITTER Before we start to discuss the splitting lever and ration design, it’s necessary to choose the right optical splitter type for your FTTH network. There are two types of splitters in our current FTTH application—PLC splitter and FBT splitter. Here we have a comparison between these two splitter types: Parameters PLC Splitter FBT Splitter Wavelength Range 1260-1650 nm Single/dual/triple window Splitting Ratio Equal division Equal or non-equal division Dimensions Small Large size for multi-channel Wavelength Sensitivity Low High Cost Low splitting channel, high price Price is lower for small channel splliter
- 6. CHOOSE PLC SPLITTER OR FBT SPLITTER As we can see in the table above, with the rapid growth of FTTH worldwide, the requirement for larger split configurations (1×32, 1×64, etc) in these networks has also grown in order to serve mass subscribers, since PLC splitters offer very accurate and even splits with minimal loss in an efficient package, they are offer a better solution for today’s FTTH applications than FBT splitters.
- 7. FTTH SPLITTING LEVEL DESIGN The PON is the optical fiber infrastructure of an FTTH network. The first crucial architectural decision for the PON network is that of optical splitter placement. The PON splitting may be achieved by centralized splitting (one-level) or by cascaded splittings (two-level or more). A centralized approach typically uses a 1×32 splitter located in a fiber distribution hub (FDH). The splitter is directly connected via a single fiber to a OLT in the central office. On the other side of the splitter, 32 fibers are routed to 32 customers’ homes, where it is connected to an ONT. Thus, the PON network connects one OLT port to 32 ONTs.
- 8. CENTRALIZED SPLITTING:USUALLY DEPLOYED IN A CROWDED CITY
- 9. CASCADED SPLITTING: USUALLY DEPLOYED IN CURB OR VILLAGES
- 10. CASCADED VS CENTRALIZED A cascaded approach may use a 1×4 splitter residing in an outside plant enclosure. This is directly connected to an OLT port in the central office. Each of the four fibers leaving this lever 1 splitter is routed to an access terminal that houses a 1×8 level 2 splitter. In this scenario, there would be a also total of 32 fibers (4×8) reaching 32 homes. It is possible to have more than two splitting levels in a cascaded system, and the overall split ratio may vary (1×16 = 4×4, 1×32 = 4×8, 1×64 = 4x4x4). A centralized architecture typically offers greater flexibility, lower operational costs and easier access for technicians. A cascaded approach may yield a faster return-on-investment with lower first-in and fiber costs. Usually, the centralized splitting solution is used in crowded city center or town areas, in order to reduce cost and easy to maintain the optical distributed network (ODN) nodes. In the other hand, two-level and multi-level cascaded splitting solution is used in curb or village places, to cover widely ODN nodes, conserve resources and save the money.
- 11. FTTH NETWORK SPLITTING RATIO DESIGN The most common splitters deployed in a PON system is a uniform power splitter with a 1:N or 2:N splitting ratio (N=2~64), where N is the number of output ports. The optical input power is distributed uniformly across all output ports. Different ratio splitters may perform differently in your network. Then, how to design your splitting ratio? According to the passage mentioned above, if you choose the centralized splitting solution, you may need to use 1×32 or 1×64 splitter. However, if you choose the cascaded splitting solution, 1×4 and 1×8 splitter may be used more often. Besides, based on our EPON/GPON project experience, when the splitting ratio is 1:32, your current network can receive qualified fiber optic signal in 20 km. If your distance between OLT and ONU is small, like in 5 km, you can also consider about 1:64.
- 12. FTTH NETWORK SPLITTING RATIO DESIGN
- 13. FTTH NETWORK SPLITTING RATIO DESIGN When to design your FTTH network splitting level, in fact, centralized splitting and cascaded splitting both has its advantages and disadvantages. We had to weight these factors and select an appropriate splitting level for our network. As for splitting ratio design, to ensure a reliable signal transmission, the longer the transmission distance, the lower splitting ratio should be used. There are series of 1xN or 2xN PLC splitters which can divide a single/dual optical input(s) into multiple optical outputs uniformly, and offer superior optical performance, high stability and high reliability to meet various application requirements.
- 14. Power attenuation calculation of Optical splitter Input attenuation of optical splitter(<1dB): OPTICAL POWER ATTENUATION Input Output1:2 optical splitter 2:N optical splitter ∵ 10 log(0.5) = - 3.01 ∴ Attenuation of 1:2 splitter: 3.01 dB Attenuation of 1:16 splitter: 12.04 dB Attenuation of 1:64 splitter :18.06 dB Input Output
- 15. FIBER ATTENUATION & POWER BUDGET Fibre attenuation relates to the fibre length The attenuation of fibre splicing point is generally less than 0.2dB Other factors may cause attenuation, such as fibre bending About 0.35 dB per km for 1310,1490nm Table G.984.2 – Classes for optical path loss Class A Class B Class B＋ Class C Minimum loss 5 dB 10 dB 13 dB 15 dB Maximum loss 20 dB 25 dB 28 dB 30 dB NOTE – The requirements of a particular class may be more stringent for one system type than for another, e.g. the class C attenuation range is inherently more stringent for TCM systems due to the use of a 1:2 splitter/combiner at each side of the ODN, each having a loss of about 3 dB. Huawei’s OLT and ONU 28 dB (Class B+)
- 16. Items Unit Single fibre OLT: OLT •Mean launched power MIN dBm +1.5 •Mean launched power MAX dBm 5 •Minimum sensitivity dBm -28 •Minimum overload dBm -8 •Downstream optical penalty dB 0.5 ONU: ONU •Mean launched power MIN dBm 0.5 •Mean launched power MAX dBm 5 •Minimum sensitivity dBm -27 •Minimum overload dBm -8 •Upstream optical penalty dB 0.5 PARAMETERS OF GPON INTERFACES (CLASS B+)
- 17. GPON LINK BUDGET (CLASS B+)EXAMPLE +5. 0 P (dBm) +1. 5 +5. 0 P (dBm) +0. 5 - 8.0 P (dBm) - 27.0 - 8.0 P (dBm) - 28.0 1490 nm 1310 nm path penalty: 0.5 dB path penalty: 0.5 dB Downstream budget: +1.5 – (-27) – (0.5) = 28 dB Upstream budget: +0.5 – (-28) – (0.5) = 28 dB Tx level Tx level Rx level Rx level 0.30 dB/km 0.42 dB/km
- 18. 18 EXAMPLE: • budget: 28 dB • 16 way splitter loss: 13.8 dB (theoretical. 12dB) • connector+splicing loss: 3 dB (24*0.1 dB + 2*0.3 dB) • aging: 1 dB • attenuation: o 0.30 dB/km – downstream o 0.42 dB/km – upstream Distance: • (28 – 13.8 – 3 – 1) / 0.42 = 10.2 / 0.42 = 24.28 km Interpretation: • for a 1:16 split, the max distance of an ONT is 24 km
- 19. CLASS C+ EXAMPLE +7. 0 P (dBm) +3. 0 +5. 0 P (dBm) +0. 5 - 8.0 P (dBm) - 30.0 (**) - 12.0 P (dBm) 1490 nm 1310 nm path penalty: 1 dB (*) path penalty: 0.5 dB Downstream budget: +3 – (-30) – (1) = 32 dB Upstream budget: +0.5 – (-32) – (0.5) = 32 dB Tx level Tx level Rx level Rx level 0.30 dB/km 0.42 dB/km -32.0 (*) Accounts for DS dispersion effects up to 60km reach (**) ONT sensitivity in C+ mode with FEC
- 20. VIDEO TRANSCEIVER SPECIFICATIONS EXAMPLE +18. 5 P (dBm) P (dBm) - 4.9 1550 nm Downstream budget: +18.5 – (-4.9) = 23.4 dB Tx level Rx level
- 21. ic MAXIMUM RANGE FOR SPLITTERS - CONFIGURATION 1:6 4 1: 8 1:1 6 Er 1:3 2 30 km 38 km 21 km 14 km 1: 2 1: 4 splitting be st cas e wor st cas e 1 : 64 14 km 10 km 1 : 32 21 km 15 km 1 : 16 30 km 23 km 1 : 8 38 km 30 km ITU-T G.984 Standar d B+ Laser
- 22. Total Link Loss Budget Based on the type of the deployed PON network, check each component in an ODN before a test. The total link loss budget in an ODN covers the following aspects: (1)Insertion loss of the optical splitter (2)Loss from fuse splicing and mechanical splicing (3)Insertion loss of the connector and adapter (4)Loss from optical transmission (5)Extra link loss (generally about 3 dB) If the CATV service is also provisioned, include the following aspects in the total link lossbudget: (6)WDM loss (loss of each WDM coupler: 0.7 dB to 1.0 dB) (7)When the 1550 nm wavelength is used for CATV transmission, the link power budget also needs to cover the following aspects: attenuation of 1550 nm wavelength (about 0.2 dB/km) and minimum optical power of the CATV receiver (-8 dBm).
- 23. ATTENUATION BUDGET FOR THE ODN LINK Item Unit Single-Mode Optical Fiber GPON Class B+ EPON PX10 EPON PX20 Optical power Optical link loss (max.) dB 28 21 26 Optical link loss (min.) dB 13 5 10 GPON optical transceiver: Class B+, 1:64/20km. EPON optical transceiver: PX10/PX20, 1:32/10 km or 1:16/20 km. The ODN link is recommended to have a certain attenuation redundancy when an ODN is planned.
- 24. Example 2 of Calculating the Total Link Loss Budget Item Type Average loss(dB) Connection point Quickconnector <0.5 Mechanical splicing ≤0.2 Fusesplicing ≤0.1 Adapter ≤0.3 Optical splitter 1:64（PLC） ≤20.5 1:32（PLC） ≤17 1:16（PLC） ≤13.8 1:8（PLC） ≤10.6 1:4（PLC） ≤7.5 1:2（FBT） ≤3.8 Opticalfiber (G.652D) 1310 nm (1 km) ≤0.35 1550 nm (1km) ≤0.21 Opticalfiber (G.657A) 1310nm (1 km) ≤0.38 1550 nm (1 km) ≤0.25 Attenuation Calculation (ODN Equipment Except Optical Cable) FDT Indoor SplitterLegend: OLT 1:2 Splitter & ODF ODF & Splicing OCCB FDT & 1:32 Splitter FAT TB ATB ONT OLT 1:2 Splitter & ODF ODF & Splicing OCCB FDT FAT TB ATB ONT 1:32 Indoor Splitter 0.3+0.1 0.1 0.1+0.3+17+ 0.3+0.1 0.1 0.1 0.5+0.3 0.30.3 0.3+3.8+0.3 Total Loss = 24.3db 0.3+0.1 0.1 0.1 0.1 0.1+0.3+17 +0.3+0.1 0.3 0.3+3.8+0.3 Total Loss = 24.4db 0.1 0.5+0.3 0.3 OLT Connector ODF OCCB Fusesplicing FAT TB Mechanicalsplicing
- 25. Total Link Loss Budget Dynamic range of the OLT optical receiver MA5680T HG850e 1:2 optical splitter 1:16 optical splitter HG850e The strength of the optical signal received on this ONT is budgeted to be -7 dB. The strength of the optical signal received on this ONT is budgeted to be -23 dB. ？Can services be provisioned concurrently on these two ONTs if their receive optical powers are within the budget? 1.As specified in the protocol, the dynamic range of the OLT optical receiver is within 15 dB. That is, the difference between the maximum optical attenuation and the minimum optical attenuation must be within 15 dB. If a range exceeds the dynamic range of the OLT optical receiver, the bit error rate (BER) increases, or even certain ONUs go offline. 2.The preceding problems will not occur if you plan an ODN in strict compliance with the protocol.
- 26. (Optional) Step 2: Test of the Transmit Optical Power of a PON Port Purpose: to test the transmit optical power of an OLT PON port to ensure that the transmit optical power is within the normal range Item Unit Single-Mode OpticalFiber GPON ClassB+ EPON PX10 EPON PX20 OLT Average transmit optical power (min.) dBm 1.5 -3 2 Average transmit optical power (max.) dBm 5 2 7 Receiver sensitivity dBm -28 -24 -27 Overload optical power dBm -8 -1 -6 1:32 optical splitter MA5680T HG850e The PON ports that pass the acceptance test need not be tested again!
- 27. (Optional) Step 2: Test of the Transmit Optical Power of a PON Port (Continued) • Required tool: optical power meter • Precautions: 1. Prepare a suitable patch cord because the connector type of the PON port is SC/PC, • but the connector type of the optical power meter is usually FC/PC(round). 2. Do use the single-mode patch cord rather than the multi-mode patch cord in a PON network. (The single-mode patch cord is yellow and the multi-mode patch cord is orange.) 3.After the test, use the anhydrous alcohol or the professional cleaner to clean the • connectors of the patch cord.
- 28. Step 3: Link Test at the Feeder Optical Cable Section(1) Purpose: to test the linkstatus from the PON port on the OLT to the IN port of the optical splitter (using the OTDR) 1:32 optical splitter MA5680T HG850e
- 29. Step 3: Link Test at the Feeder Optical Cable Section(1) Required tool: OTDR Precautions: 1.Most of OTDRs available to the field engineers cannot penetrate the optical splitter; therefore, when you perform a test in the downstream direction from the OLT, the distance displayed on the OTDR is the distance between the OLT and the optical splitter. 2.When using the OTDR to perform a test, ensure that the optical fiber is in the “black” state (that is, no light source exists in the optical fiber link). Otherwise, the test results are not convincing. In addition, when performing a test in the upstream direction from the optical splitter, remove the optical fiber connected to the PON port on the OLT， record the test results, and ensure that there is no rogue ONT or no ONT that is in the always active state. 3.Try to perform bidirectional tests. 4.(Mandatory) After the test, use the anhydrous alcohol or the professional cleanerto clean the connectors of the patchcord.
- 30. Step 3: Link Test at the Feeder Optical Cable Section(2) Purpose: to test the link status from the PON port on the OLT to the IN port on the optical splitter (using the optical power meter instead of the OTDR) 1:32 optical splitterMA5680T HG850e Light source Optical power meter Optical power meter Page30HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
- 31. THANK YOU