National SDH Network – Optical Planning ExerciseExercise description• A national SDH ring network is to be implemented and you are asked to undertake the verificationand design of the optical layer.• The bit rate is 2.5 Gbits/sec (STM-16) throughout• As this is a national telecoms network you must use products that comply with international ITUspecifications• At … Continue reading “Optical Planning Exercise | My Assignment Tutor”
National SDH Network – Optical Planning ExerciseExercise description• A national SDH ring network is to be implemented and you are asked to undertake the verificationand design of the optical layer.• The bit rate is 2.5 Gbits/sec (STM-16) throughout• As this is a national telecoms network you must use products that comply with international ITUspecifications• At the end of the exercise you should be able to specify the ITU system type (“interface class”) to beused on each link in the ring• For simplicity of spares provisioning you are asked by your company to try to use only one ITUsystem throughout – but this may not be possible!• In the future this network may be upgraded to 10 Gbits/sec (STM-64) ,a full investigation of thepossibility of this being possible should be carried out.Information supplied• Route diagrams, distances and other data• ITU-T Recommendation G.957, paying particular attention too Section 5: Classification of interfaceso Section 6: Parameter definitions, but for the purpose of this exercise you can ignore 6.1,6.2.4, 6.2.5 and 6.3.3o Section 8: Optical engineering approach• Selected manufactures system planning data for systems that are compliant with but exceed ITUspecs (Siemens)• ITU-T G.652Outline network specifications• Southern ring for Ireland• STM-16 (2.5 Gbits/s) Add Drop Multiplexer (ADM) based ring network• Wavelength is 1550 nm throughout the network• ADM node locations:o Dublin, Naas, Carlow, Waterford, Cork, Limericko Ennis, Galway, Ballinasloe, Athlone, Kinnegad• Average intersplice distances are 600m• Installation contractor can guarantee splice loss to be less than 0.03dB• Four FC/PC connectors are needed per system, including those on the Optical Distribution Frame(ODF), but as per ITU excluding those at the transmitter and receiver• Worst case connector pair loss is 0.15dBProposed networkRoute distances FromToRoute distance in kmDublinNaas31NaasCarlow50CarlowWaterford77WaterfordCork122CorkLimerick102LimerickEnnis36EnnisGalway63GalwayBallinasloe67BallinasloeAthlone24AthloneKinnegad65KinnegadDublin64 Siemens STM-16 Interface, L-16.2, L-16.3 and JE-16.2*, JE-16.3* UnitsL-16.2L-16.3JE-16.2JE-16.3Source characteristics at point S(as per ITU-T Rec. G.957)Laser diodeDFBDFBOptical wavelengthnm1510 to 15601530 to 1560Spectral widthnm0.60.6Side-mode suppressiondB> 30> 30Transmit leveldBm-1 to +2+2.5 to +5Minimum extinction ratiodB8.28.2Fibre-optic route characteristicsbetween points S and R (as per ITUT Rec. G.957)Cable return loss at point S(including connector)dB> 24> 24Tolerated chromatic dispersionps/nm18002400Allowable optical attenuationdB8 to 2514 to 31Receiver characteristics at points R(as per ITU-T Rec.957)Receiver diodeAPDAPDReceive leveldBm-28-30.5Maximum permissible opticalreceive leveldBm-6-9Losses due to transmitter noise anddispersiondB 30> 30> 30Transmit leveldBm+10 to +13+13 to +16+13 to +16Minimum extinction ratiodB101010Fibre-optic route characteristicsbetween points S and R (as per ITUT Rec. G.957)Cable return loss at point S(including connector)dB> 24> 24> 24Tolerated chromatic dispersionps/nm450045004500Allowable optical attenuationdB19 to 3622 to 3931 – 51Receiver characteristics at points R(as per ITU-T Rec.957)Receiver diodeAPDAPDAPD withpreamplifierReceive leveldBm-28-28-40Maximum permissible opticalreceive leveldBm-6-6-15Losses due to transmitter noise anddispersiondB2 dB?• Pick a typical medium range link (say Naas-Carlow, 50 km) to test your model, using an ITU L-16.2compliant system• The correct answers for Naas-Carlow are:o Attenuation is within range at 16.84 dBo Fibre dispersion less than limit at 850 pso Margin adequate at 8.16 dB• Using the model and the available data draw up an ITU G-957 power budget and identify any criticalroutes.• Hence:o Suggest solutions for “problem routes”o The Siemens data supplied will assist in finding solutions to problem routes.o Check that your solutions will work by carrying out power budget• Finally define a correct ITU system type for each routeReportPrepare a written report with the following structure:1. A brief introduction 1-2 pages long outlining the objective and context of the assignment andoutlining your approach to a solution. (15 Marks)2. Result of 2.5 GB ring network design (35 Marks)a. A concise evaluation of the outcomes of the power budgeting models for each link, focusingin particular on the problem links (eg. very long or very short links)b. A discussion of your proposed solutions and any conclusions you have. (e.g Does your designuse only one ITU System throughout the whole network)c. A table proposing a system type for each link in the national SDH ring, specifying the systemtype to be used and any other comments or qualifications reached.3. During the design of this project you have been asked to consider how the system could beupgraded to 10 Gbps. Using G.691 and appropriate power budgeting techniques discuss how thismay be done. (50 Marks). This is a complex task and should include.a. Power budgets for each linkb. System types identified for each linkc. Problems that may arise when trying to upgraded. Any solutions that you can suggest to overcome problem linkse. Any other relevant information4. An appendix containing the relevant Excel spreadsheet power budget models used.Submission11:59pm Sunday March 21st.In the assignment section on BrightspaceFiletype Report in PDF and spreadsheets in ExcelFilename Firstname Lastname.pptx e.g. Thomas Freir.pdf (No underscores or other symbols)Any material from the web or other sources should be referenced.Plagiarism will be handled in line with the General Assessment regulations.Late assignments will be marked as follows. Up to one week lateMarked out of 75%Up to two weeks lateMarked out of 50%Up to three weeks lateMarked out of 25%More than three weeks late0% Suggestions1. Spell check and grammar checks should be used (e.g. Grammarly).2. Attend the relevant lab to gain a global understanding of the question being asked.3. Ensure your power budget model is correct and that you are using the correct values from thestandards.4. Please make sure you have included all the required parts from the report section.5. Use the lab to ask question and make suggestions for section 3.GradingPlease see the rubric associated with the assignment in Brightspace.
