This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
■Objective: Promotion of optical fiber distribution to/in detached houses and apartment houses.
■Sub-committee Establishment:“Intra- Building Optical Wiring SC” established April 1996Role; 1) Research of latest technology
2) Standardization of technology by publishing technical papers (TP)
■TP publication:Three TPs published since August, 2007 (now third edition)TP01/BW-2011; Optical Fiber Distribution System for Detached Houses in FTTHTP02/BW-2011; Optical Fiber Distribution System for Apartment Houses in FTTHTP03/BW-2012; Plastic Optical Fiber Distribution System for Customer Premises
Scope Covered by TP01 & TP021. Introduction of silica glass optical fibers in detached houses and apartment houses and their connection to generic cabling boxes.2. Guidelines for installation, maintenance, management, and performance standard of their parts and materials regarding optical fiber distribution systems.
Types of In-house Optical Cabling Methods1. Cabling using conduits; In a newly-built house, in-house conduits are installed in the internal wall. 2. Exposed cabling; For an already-built house, an optical cable is wired along the internal wall. Three methods are used: “Exposed cabling using optical staples”, “Cabling with cable protector”, or “Free cabling“.
“Free cabling”“Cabling with cable protector”2) Exposed cabling
Example of in-house optical cabling using optical outlet installed on internal wall
Optical Fiber Cable for Detached Houses■Two types of optical fiber cables are used for FTTH in detached houses. 1. Optical drop fiber cable is used to introduce line into the house.2. Indoor optical fiber cable for in-house distribution.■Silica glass single-mode (SM) optical fibers.■Optical fiber with a low bending loss has recently been used to halve the permissible bending radius to 15 mm.
2) Indoor optical fiber cable1) Optical drop fiber cable
■New indoor optical fiber cables for wiring through spaces around doors or windows for existing condominiums or small apartments are developed by NTT. ■Excellent installation workability has been achieved due to the good bending loss performance and optimum cable configuration. ■The new cable can be drawn into dwellings without creating a hole in the wall.
2) Indoor optical fiber cables for restricted spaces
* K. Kuramoto, H. Minami, M. Ida, T. Shimizu, A. Daido, Y. Aoyagi, and K. Takamizawa, “Flexible Optical Wiring Technology for Existing Buildings,” Proc. IWCS’12, 2012.
FRP: Fiber Reinforced Plastic HAF: single mode Hole Assisted Fiber(Bending loss is smaller than G.657)
Cabling and Connection /Maintenance and Management
■Generally, a telecommunication service provider is responsible for the outdoor cabling of optical drop fiber cable and the in-house cabling of indoor optical fiber cable and installing an ONU.■Maintenance and management should be performed in accordance with the following points.
1) Record of installation of new or additional cabling and equipment
2)Dissemination of warnings about in-house optical facilities- Do not touch the endface of the optical connector to avoid any increase in connection loss. - Do not look at the endface of an optical connector because the laser beam may damage the eyes.- When moving furniture, be careful to do not damage the optical fiber cable. - Warning about optical fiberIf the indoor optical cable is cut by mistake, do not touch the end. The optical fiber may cause a wound by piercing part of the body.
Test and Performance Standards■Test of optical loss or optical power level at ONU is conducted after installing and connecting an optical fiber cable. Test results must meet the performance standard. ■The test methods and performance standards differ for each telecommunication service provider.■In FTTH, with the spread of video services, PON optical power meters are used, which can measure different wavelengths 1490 nm (for Internet services) & 1550 nm (for video service) simultaneously.
■For the backbone cable, the required number of fibers are installed in each dwelling unit.■The distribution method should be determined based on installation difficulty, EPS space, and cost. ■The three methods shown below are used.
Termination at Dwelling Unit■A horizontal cable is terminated in a generic cabling box or an optical wall outlet.■An optical connector is connected on-site at the end of the horizontal cable. Alternatively it is fusion or mechanically spliced with an optical cord using a connector. ■The optical connector is usually an SC type optical connector.■Cabling at a dwelling unit is shown below.
1) With generic cabling box(mainly for new apartment houses)
2) Without generic cabling box(mainly for existing apartment houses)
■The testing methods and performance standards depend on the telecommunication service provider. ■The performance standard example below is shown as a reference.
Optical Cabling Model in Example Loss Calculation
Connector Fusion Fusion Fusion Connector
Backbone cable
Horizontal cable
PD board
50 m 20 m
MDF Generic cabling box
Optical fiber cable : single-mode optical fiber with standard loss of 0.4 dB/km - Cabling distance: 70 m- Measurement wavelength: 1.31μm- Fusion splicing loss: 0.2 dB or smaller- Optical wall outlet connection loss: 0.7 dB or smaller- Number of fusion splices: 3Loss of optical fiber only = 0.07(km) x 0.4(dB/km) = 0.03(dB)Optical fiber splicing loss = 0.2(dB) x 3 (points) = 0.6(dB)Optical connection loss = 0.7(dB)Performance standard = 0.03(dB) + 0.6(dB) + 0.7(dB) = 1.33(dB)
Basic Configuration of POF Distribution System■Plastic Optical Fiber (POF) is used to replace a LAN cable or coaxial cable in detached or apartment houses.■Acrylic Resin-Type POF is used for in-house cabling, Fluoropolymer-Type POF is used for backbone cabling in apartment houses.■POF is distributed from a media converter (M/C) inside a generic cabling box to an another M/C via a telecommunication outlet in each room using a pre-installed conduit.
Example of cabling configuration of acrylic resin-type POF for newly constructed detached houses
POF Cord or Cable■Single cord and duplex zip cord, both of which are POFs directly buffered with resin, are used as acrylic resin-type POFs. ■Generally, a loose duplex cable (flat type) with tension lines, or a duplex cable with aramid yarn is used for fluoropolymer-type POFs.
a) Duplex zip cord (2.2 x 4.4 mm) b) Duplex cable (4.0 x 5.5 mm)
(a) Loose duplex flat cable (b) Loose duplex zip cable
2) Typical duplex cables for fluoropolymer-type POFs
1) Examples of acrylic resin-type duplex POF cord and cable
Optical Loss Measurement Procedure for POF■An optical fiber loss test for POF is also conducted using an optical power meter at an operating wavelength after installing an optical cable and completing the termination process.
The testing procedure (simple method) is as follows: 1) Turn on light source and allow to warm up for about 10 minutes;2) Connect a launching optical fiber cable to light source and to optical power meter and measure optical power (Pin); 3) Connect cable under test to launching cable and optical power meter and measure optical power (Pout);4) Calculate loss value in accordance with formula below:
Note 1: Typically 15 to 35 μm smaller than cladding diameter*1: Theoretical NA for PSI-XX, effective NA for PGI-XX *2: At 650 nm, under equilibrium mode launch condition*3: At 650 nm, launch NA = 0.3*4: At 850 nm
Certification of Optical Fiber Cabling Technology ■Information Network Installation Professional (iNIP) is an NPO qualification certified by the Advanced Info-Communications Promotion Community (ICP).
ICP has been approved as a test organization by the Ministry of Health, Labor and Welfare. A vocational ability test related to Telecommunications Distribution Technology has been put into operation with ICP.
■However each telecommunication service provider has its own certification program. This is because the test methods and performance standards differ depending on the provider.
■Seminar courses on optical fiber cabling technology including fiber treatment, splicing, connection, testing and troubleshooting have been held in accordance with the iNIP by individual telecommunication carriers, optical cable manufacturers, construction companies, and so on.
Improvement of Optical Fiber Distribution Techniques
■Construction techniques have been improved through National and World Skill Competitions.■50th National Skills Competition was held in Nagano Prefecture in October 2012.The Telecommunications Distribution Technology Skill competition was won by Mr. Utsunomiya (KINDEN CORPORATION). This also qualifies him for the 42nd World Skills Competition (Leipzig, Germany, July 2013 ). The winner of this competition will qualify for international competitions as a representative of Japan.
Mr. Utsunomiya (KINDEN CORPORATION) as a winner in Skill of Telecommunications Distribution