{"id":10173,"date":"2022-02-14T17:40:29","date_gmt":"2022-02-14T17:40:29","guid":{"rendered":"http:\/\/141.23.68.248\/wp\/?page_id=10173"},"modified":"2022-02-15T17:02:50","modified_gmt":"2022-02-15T17:02:50","slug":"fiber-optic-cable","status":"publish","type":"page","link":"http:\/\/141.23.68.248\/wp\/?page_id=10173","title":{"rendered":"Fiber Optic Cable"},"content":{"rendered":"

1. Introduction<\/strong>
\nThis assignment aims to conduct a life-cycle analysis of a tower of a wind turbine
\nas well as a multi-criteria decision-making analysis.
\n2. Civil engineering sub-system\/ design options
\nAs a sub-system, the type of installation or the pipes\/protective tubes and the buried expansion are
\nconsidered and analysed in this work. The fibre optic cables are laid underground throughout
\nGermany. The fibre optic cables transmit the light pulses to the receiver and must be protected from
\nexternal influences by protective pipes.
\nIn order to determine the required materials for the cable protection tubes, the following
\nparameters must be taken into account:
\no Length of the buried fibre optic cable
\no Length of the protective tubes
\no Stiffness
\no Material used
\no Transport and installation options
\nTo calculate the amount of material required, the length of the fibre optic cables to be laid and the
\nstiffness of the tubes are decisive.
\nThere are not many options for protecting or laying the fibre optic cables. Plastic pipes are often used
\nas the material, which are then laid in a trench, see figure 2. Furthermore, fibre optic cables can be
\nintegrated into sewage pipes, whose protective pipe is the surrounding concrete, see figure 1, and
\nfibre optic cables can also be routed along wooden poles, which consist of metal-free air suspension
\ncables (ADSS cable = All Dielectric Self Supporting), see figure 3<\/p>\n

 <\/p>\n

\"y\"<\/a><\/p>\n

3. LCA<\/strong>
\n3.1 Goal and scope<\/strong>
\nGOAL:<\/strong>
\nThis life-cycle assessment examines three design options of fibre optic cable laying and therefore
\nidentifies their events and inventory throughout their life-cycles. In addition, specific aspects of the
\nimpact of the installation variants are chosen and analyzed. The aim is to obtain information on the
\nenvironmental impact of the various design options with regard to different inputs. Furthermore, the
\nbest installation option based on the defined inputs is to be crystallized based on this study. This
\nstudy will be conducted only for academic learning purposes and thus making them comparable. The
\nscope of this assignment will therefore be limited to the set of tasks which were required and targets
\nstudents and teacher. As the background research and conducted data was simplified, this paper
\ndoesn\u2019t claim completeness or intends public assertions.
\nSCOPE:
\nProduct function: The task of the chosen installation method is the fast, direct and safe way of
\nstoring the fibre optics. The selected installation method protects the fibre optic cable from external
\ndamage and is intended to provide a fast connection of the fibre optic cable from the main centre to
\nthe house or distributor.
\nFunctional unit: The functional unit of a tower can be defined as the number of years in operation. In
\nthis way, one can compare the different types of installation and compare the results with other
\nstudies.
\nSystem boundary: A simple product tree of a fibre optic network is shown in figure 3.<\/p>\n

\"we\"<\/a><\/p>\n

\u00a0Figure 3: product tree of fibre optic systems<\/p>\n

3.2 Life- Cycle Time Span<\/strong><\/p>\n

It is unusual for glass fibre networks to change the type of installation or to replace the protective
\npipes in which they are installed. Therefore, no maintenance work is foreseen for fibre optic
\nnetworks. Maintenance work only takes place for data transmission by Telekom, which tends to be
\nactive at night, so that users do not notice it. This view excludes catastrophic events where cables
\nand protective pipes have to be patched. Therefore, in this work, rather smaller maintenance events
\nsuch as cleaning of the suspended cables, stability checks or replacement of patches\/connectors are
\nconsidered. All these measures require only a very small amount of material, as the patches, for
\nexample, are relatively small as a component. The most important inspected interventions that an
\ninstaller has to consider when maintaining the net are shown in Table 1. As can be seen, no cleaning
\nwork is carried out for the buried protective cables and the waste water pipes. Here, it is hardly
\npossible to carry out annual maintenance because of the high costs involved when excavation work
\nhas to be carried out. Furthermore, the cables inside the concrete sewage pipes are also difficult to
\nmaintain, as the necessary expensive construction clearance has to be created here as well. We
\ntherefore assume zero years for the cleaning work in options 1 and 2.<\/p>\n

\"rt\"<\/p>\n

3.3 Life- Cycle Inventory<\/strong><\/p>\n

The installation variants examined here consist of three different materials: PE-HD, concrete and
\nmetal-free PE. The following amounts were determined by research for the installation of 100 m of
\nfibre optic cable:
\nOption 1: empty conduit cable (PE-HD) 119 kg
\nOption 2: sewage pipes (integrated in concrete pipes) 252000 kg
\nOption 3: Suspended cables (“ADSS- all dielectric self- supporting”) 26 kg<\/p>\n

This results in further figures for energy consumption, CO2 emissions and the glass fibres to be laid
\nfor the production of the various cables. These are presented in the table, which shows the
\nquantities of materials used during the entire life cycle of the glass fibre network. Since the research
\nprovided little information about the ADSS cables, assumptions were made here. The values for the
\nPE plastic cables were used for the ADSS cables. Furthermore, it should be noted here that it is
\nassumed that fewer pipes can be installed in the sewage concrete pipes and above ground (on the
\nwooden poles) due to the lack of space. The amounts are also shown in figure 5.<\/p>\n

4. Multi- Criteria Decision Analysis<\/strong><\/p>\n

The multicriteria decision analysis was carried out using a TOPSIS analysis in Rstudio. The indicators
\nweight and glass fibre were weighted with 0.1, while energy and CO2 were weighted with 0.4. The
\nlatter two indicators are considered “more important” for the environment. Although energy and
\nCO2 are to some extent interdependent, they were ranked higher because glass fibre is often
\nrecycled and reused in the construction industry, for example. The recycled plastic is installed in
\nsewage pipes or wind turbines.<\/p>\n

It is clear that in TOPSIS 1, design option 2 is ranked as the best option with 43.78%, which is due to the low values for energy and
\nCO2 consumption. Option 1 scores just below option 3 grade 28.07%.\u00a0We also see that the values are very close, which is due to the
\nmissing information for the ADSS cables. Once the positive and negative ideal solutions are included in the analysis, we see
\nthat the options are ranked relatively equally. In the objective comparison, the TOPSIS 1 analysis makes more sense as option 1 has the worst scores in 3 out of 4 categories and should therefore not be considered equivalent to option 3. As a
\nconclusion, the positive and negative numbers for the ideal solution should be improved to get a
\nmore accurate result of this analysis.<\/p>\n

5. Discussion<\/strong><\/p>\n

Regarding the trade-offs made in this task, the most important is the limited choice of impact or
\nconsumption categories. Only a small range was analysed, while other equally important figures
\ncould not be proposed. Other impacts were not taken into account, for example the construction
\nwork for laying or the execution work for creating the wooden masts. Here, further emissions are
\nemitted and transport also plays an important role in the costs of the laying work.
\nOn the same hand, the choice of categories was very varied, so that different aspects could influence
\nthe results. Resuming to this, further approaches could concentrate more on a specific field, for
\nexample only the gas emissions during the life cycle.
\nIn addition, the influence of the plastic cables on the CO2 balance is higher than that of the concrete,
\nwhich leads to a worse CO2 balance at the time of construction. However, it must be taken into
\naccount that laying plastic pipes can last up to 30 years, so the carbon footprints can balance out
\nafter the lifetime of the cables. To obtain more accurate results, different life spans should be
\nconsidered.<\/p>\n

6. Sources<\/strong><\/p>\n

https:\/\/docplayer.org\/6202540-Alho-architektur-die-vielfalt-des-modularen-raums.html
\nhttps:\/\/www.researchgate.net\/figure\/Life-cycle-environmental-impacts-from-production-of-glassfiber-
\nchina-reed-fiber-Epoxy_tbl2_222403148
\nhttps:\/\/community.fs.com\/de\/blog\/tips-for-using-and-maintaining-fiber-patch-cables.html
\nhttps:\/\/www.schoengen.de\/fileadmin\/website\/download\/prospekte\/pdf\/2_1_Schutzrohre_PEHD_
\nStangenware_2016_A4_oP.pdf
\nhttps:\/\/www.rinninger.de\/index.php\/rohre-titel\/betonrohre-kreisrund
\nhttps:\/\/www.rehau.com\/downloads\/510054\/katalog-rehau-telekommunikation.pdf
\nhttps:\/\/www.fbsrohre.de\/fileadmin\/content\/shop\/nachhaltigkeit\/fbs-expertise-oekologie.pdf
\nhttps:\/\/www.oeko.de\/fileadmin\/oekodoc\/Digitaler-CO2-Fussabdruck.pdf
\nhttps:\/\/www.deutschlandfunk.de\/recycling-von-glasfaser-kunststoff-aus-windkraftraedern-100.html<\/p>\n","protected":false},"excerpt":{"rendered":"

1. Introduction This assignment aims to conduct a life-cycle analysis of a tower of a wind turbine as well as a multi-criteria decision-making analysis. 2. Civil engineering sub-system\/ design options As a sub-system, the typeContinue reading<\/a><\/p>\n","protected":false},"author":119,"featured_media":10184,"parent":10034,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-10173","page","type-page","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/pages\/10173","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/users\/119"}],"replies":[{"embeddable":true,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10173"}],"version-history":[{"count":6,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/pages\/10173\/revisions"}],"predecessor-version":[{"id":10632,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/pages\/10173\/revisions\/10632"}],"up":[{"embeddable":true,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/pages\/10034"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=\/wp\/v2\/media\/10184"}],"wp:attachment":[{"href":"http:\/\/141.23.68.248\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}