Tài liệu Cabling Standard - TIA 758 - Customer Owned Outside Plant pptx

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Tài liệu Cabling Standard - TIA 758 - Customer Owned Outside Plant pptx

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A A N N S S I I / / T T I I A A / / E E I I A A 7 7 5 5 8 8 Customer Owned Outside Plant Disclaimer This information is collected and composed by QUANG DUNG TECHNOLOGY from www.Cablingdb.com. All information is copyrighted by Cablingdb.com. Standards Preservation This section is not part of the original standards documentation. The purpose of this document is to provide an easy to understand, condensed version of the original document. A basic level of telecommunications is assumed. For further information on terms and definitions see our Glossary of Terms section. Whether you are renovating your existing cable plant or installing a new one, Cablingdb.com urges you to investigate a standards based solution. This document is not meant to replace the original standards developed by the various standards bodies and we urge you to purchase the original documents through www.tiaonline.com. AUTHORIZED & EXCLUSIVE DISTRIBUTOR Head Office Suite 202, The Colonnade Building, 27 Nguyen Trung Truc St., District 1, Hochiminh City, Vietnam Tel: 84.8 823-1693 Fax: 84.8 823-1665 Hanoi Office A11, 3/Fl., Horizon Hotel, 40 Cat Linh St., Dong Da District, Hanoi, Vietnam Tel: 84.4 736-7055 Fax: 84.4 733-2470 Website: www.qd-tek.com.vn Email: info@qd-tek.com ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 2 of 35 Table of Contents Cabling Infrastructure Introduction Building Entrance Terminals Cabling Connecting Hardware Copper Splicing Fiber Splicing Pressurization of Air Core Cables Pathways and Spaces Introduction Aerial Bridge Crossings Conduit Direct Buried Handholes Maintenance Holes Pedestals/Cabinets/Vaults Utility Tunnels ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 3 of 35 CABLING INFRASTRUCTURE General Outside Plant Definition Outside plant is defined as those communications pathways, spaces and media which are located outside of the building walls. This includes, but is not limited to the cable (copper and fiber), splices, conduit, manholes, handholes, poles and hardware related to the attachment and support of the various forms of media. Function The function of customer-owned OSP cabling infrastructure is to provide connections between building entrance facilities, structures in a campus environment, or telecommunications pedestals or cabinets. Customer-owned OSP cabling consists of the backbone cables, splices, terminations, and patch cords or jumpers used for backbone-to-backbone connection. The customer-owned OSP cabling infrastructure shall meet the requirements of the local authority(s) and local codes. History Prior to the divestiture of the Bell Companies, they were the ones who looked after the OSP infrastructure. Now, owners have a choice of who owns, installs and manages the infrastructure. One of the main issues is the lack of standardization in requirements and installation methods. It is now up to the owner to take on the burden of the decision making process of what products to use and who to get to install them. Regardless of any of the above issues, the designer has to be aware of: • Pathways and spaces • Cabling • Hardware Bonding and grounding • Rights of way • System documentation Safety The designer and installer must also be aware of the safety issues involved in working in an OSP environment. Depending on the route the installer may be working at the top of an aerial truck, or in a manhole or trench. It is everyone's responsibility to ensure that proper safety precautions are taken. If the route cannot be constructed without compromising the safety of those involved, the route should be altered. Topology The recommended topology for customer-owned OSP cabling is a star configuration. This is the same type of star topology that is recommended for a local area network. In the case where a star topology cannot be used, consider a hierarchical star. By implementing a star, or hierarchical star the system can be managed and maintained easier than other topologies. The same advantages of a LAN star topology can be found in a campus star topology. ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 4 of 35 In a star topology one of the buildings will act as the MC and feed out the backbone cables to the various buildings. In a hierarchical star there may be a building acting as an MC, and the another group of buildings is served by a building acting as an IC. Other types of topologies that may be used are a bus or tree and branch topology, physical wired star/virtual ring and a ring. A ring topology may be a single path ring, a counter rotating redundant ring or several attached rings. Each type has its disadvantages and advantages depending on the layout of the network, media chosen and applications being run, and as well, the overall goal of the network. Recognized Cables An OSP environment may support several applications such as CATV, LAN, WAN, and voice over a variety of distances and in a number of different physical and environmental settings. For these reasons OSP cable must be able to support all of these environments and applications. Therefore several cables are recognized by the standards. The recognized media include: • 50/125µm optical fiber cable • 62.5/125µm optical fiber cable • singlemode optical fiber cable • 100 ohm twisted-pair cable • 75 ohm coaxial cable A single media may not satisfy all of the requirements of the owner, and therefore several types of media may be required. When possible the various media should use the same pathways to keep administration and costs down. In making this choice, factors to be considered include: • flexibility with respect to supported services • required useful life of backbone cabling • site size and user population Bonding and Grounding Bonding and grounding shall meet the appropriate requirements and practices of applicable authorities and codes. Additionally, grounding and bonding within buildings shall conform to ANSI/TIA/EIA-607 requirements, and the National Electrical Safety Code (NESC) between buildings. Failure to follow these standards and codes can result in interference, improper operation and possible harm to those operating the system. ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 5 of 35 BUILDING ENTRANCE TERMINALS General This portion of the standard covers the requirements for building entrance terminals located at the cabling entrance to building facilities where the transition between inside and outside environments occur. Building entrance terminals can be used on the outside of the building or on the inside, with the inside being the primary choice. Building entrance terminals are available in sizes such as 2-pair, 4-pair, 6-pair, and multiples of 10- and 25-pair. It is desirable that terminal blocks for be of the IDC type, such as 110. Terminal Protection Protected terminals Protected terminals shall meet the primary protection requirements of UL 497 and the mechanical and reliability requirements of this Standard. CABLING Twisted Pair Cable General This section covers the requirements for multi-pair customer-owned OSP twisted-pair cables that are used in campus environments. Coaxial cable and fiber optic cable are covered later in the section. OSP cables are intended for the distribution of communications signals which carry voice and data. Enhanced performance, referred to as Broad Band Outside Plant (BBOSP) cables are intended for the distribution of signals to carry voice, high-speed data, and video. Cables used shall: • meet the requirements of the AHJ and applicable codes • consist of 19 AWG, 22 AWG, 24 AWG, or 26 AWG thermoplastic insulated solid copper conductors in one of the designs listed below. Cable Construction Types OSP and BBOSP cabling is installed in aerial, duct (underground), and direct-buried applications. A filled cable may be used in all applications, whereas an aircore cable is not recommended for direct buried use. Aerial (self-support and lashed) Aerial cables come in two major classifications, self supporting and non self supporting. Self-supporting cable has a steel support messenger designed into the cable. This type of cable is more sometimes referred to as "Figure 8" cable because its cross sectional view looks like an "8". OSP cable intended for aerial use without a support messenger shall be lashed to a support messenger. Direct Buried Cable ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 6 of 35 Direct buried cables are placed directly into the ground through a variety of methods such as vibratory plough or trenching. These cables shall have a moisture barrier compound within the cable to prevent moisture from entering the cable should the outer sheath be penetrated. Underground Cable Underground cables are placed in a duct system rather that directly into the ground. This helps prevent against rodent and environmental damage. Cables placed in a duct system may, or may not contain a moisture barrier compound. Buried Service Wire Buried service wire is intended for use when extending from the distribution cable to the entrance facility of a building. Aerial service wire Aerial service wire is used when extending from the distribution cable terminal to the entrance facility of a building. The maximum span length shall not exceed 60 m (200 ft). Screened Cable (internally) Internally screened OSP cable is for use with pulse code modulation (PCM) transmission. The screens separate cable pairs within the core into compartments (i.e., one containing the transmit pairs, and the other the receive pairs) for improved crosstalk performance over regular OSP cable. Cable Performance Cable Type Performance Specification Filled OSP ANSI/ICEA S-84-608 Air Core OSP ANSI/ICEA S-85-625 Broadband Filled OSP (BBOSP) ANSI/ICEA S-99-689 Broadband Air Core OSP ANSI/ICEA S-98-688 Filled Screened Cable ANSI/ICEA S-84-608 Air Core Screened Cable ANSI/ICEA S-85-625 Buried Service Wire* ANSI/ICEA S-86-634** Aerial Service Wire* ANSI/ICEA S-89-648** Notes * The performance requirements of the cable should be verified to ensure they meet the overall design criteria. ** The maximum length of the cable shall not be more than 213 m (700ft) 75 Ohm Coaxial Cabling General Coaxial cable used in backbone OSP applications is 75 ohm semi-rigid cable referred to as trunk, feeder and distribution coaxial cable. The cable is available in sizes ranging from 10 mm to 29 mm (0.412 in to 1.160 in) in diameter. In designing a coax system, the designer must understand the relationship between attenuation and the ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 7 of 35 diameter of the cable. Since attenuation is lower with a larger diameter cable, the cable choice will affect the number of amplifiers in the system. Cable Performance Performance, mechanical and electrical requirements of coaxial cable are goverened by the Society of Cable Television Engineers (SCTE). This group is somewhat equal to ANSI/TIA/EIA in that they specify the criteria for proper installation, testing and performance of coaxial systems and products. Mechanical and electrical requirements for 75 ohm trunk, feeder and distribution coaxial cable are found in the Society of Cable Television Engineers (SCTE) document IPS-SP-100. Connecting Hardware Connecting hardware used with OSP Coaxial Cable is referred to as "N" type connecting hardware, and it is designed to fit each particular cable size and type. Connecting hardware includes connectors, taps and splitters. The designer should verify with the cable manufacturer regarding connecting hardware that is compatible with their cable. Installation Requirements The SCTE document "Recommended Practices for Coaxial Cable Construction and Testing, Issue 1, Section 1" provides the necessary information required for proper installation practices. Testing The minimum test requirements for 75 Ohm coaxial cable shall include a continuity test for the center conductor and shield. The installer may test the following parameters; • Attenuation • Length • Characteristic impedance • Return loss • DC loop resistance Optical Fiber Cabling General This section details the requirements of fiber optic cables as they apply to an OSP system. Although connecting hardware and splices may be part of this system, they are described in more detail in their respective sections. The designer should take into consideration the following: • bandwidth requirements of the system (short and long term) • system length • system capacity • route redundancy Recognized Cables ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 8 of 35 Both multimode fibers and singlemode fibers or a combination of these fiber types are acceptable. When both types of optical fibers are combined, some means of segregating the fibers by type shall be used. Cable Performance OSP optical fiber cable shall meet the performance requirements of ANSI/ICEA S-83- 640 and ANSI/TIA/EIA-568-B.3. Cable Construction Types OSP optical fiber cable shall meet the physical requirements of ANSI/ICEA S-83-640. Optical fiber cables come in several designs with many construction options. Duct Cables Duct cables are generally non-armored cables. All-dielectric versions (no metallic components), which incorporate a nonmetallic central member, are available and are suitable for duct, aerial or conduit placement. Armored Cables Armored cables have a steel armor layer added under the outer cable jacket. The armor is added to improve the rodent resistance capability of a direct-buried cable, and also provides an extra layer of protection against other factors, such as rocky soil. Aerial Cables Aerial cables typically have the same cable construction as duct cables and com in two versions, self supporting and Figure 8. All-dielectric optical cables are recommended when practical since these cables are not as susceptible to lightning strikes, are not subject to induced voltages and are not required to be grounded as are cables with metallic components. Self-Supporting Cables These cables are designed to be installed without the need for a pre-installed messenger (Figure 8). These cables may or may not have metallic components in them. An All Dielectric cable contains NO metallic components. Self supporting cables require no lashing and may therefore be easier to install than a Figure 8 cable or a lashed cable. There may be load, length and span length limitations on these cables depending on wind and ice conditions in the geographic area the cable is being installed in. The designer should check for any special hardware required. Figure 8 Cables As with copper, these self-supporting cables incorporate a metallic messenger in a common sheath. Indoor/Outdoor Cables ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 9 of 35 Some cables can be installed in both outdoor and indoor locations. This type of cable combines the attributes of an outdoor cable, ie: water blocking and UV resistance, as well as a flame resistant jacket (riser rated)suitable for indoor applications. This avoids transitioning to an indoor fiber, thereby reducing costs and system losses due to splicing and/or connectorization. However, the designer should be aware that the cost of this type of fiber is higher than regular outdoor fiber, and that there is a cost point where using the two individual fiber types is more advantageous. Drop Cables Drop cables are typically small diameter, low fiber count cables with limited unsupported span distances. They are used to feed a small number of fibers from a higher fiber count cable into a single location. CONNECTING HARDWARE OSP Twisted-Pair Connecting Hardware General The connecting hardware includes terminal blocks that are used for transition from distribution cable to service wire, and cross-connect blocks that are used for cross- connection between feeder and distribution cables. Environmental Compatibility Connecting hardware shall: • function for continuous use within the temperature range of -40°C to 70°C (- 40°F to 158°F) • allow for connecting and removing wires from -18°C to 50°C (0°F to 122°F) • have terminals that are resistant to corrosion from moisture, atmosphere, UV degradation, insecticides and herbicides. Materials Metal components shall: • be resistant to or protected against general corrosion, stress corrosion cracking and pitting. • not produce significant galvanic corrosion effects on other metals in pedestal terminal closures or aerial cable terminals. Plastic parts shall: • be resistant to fungi, heat, solvents, and stress cracking agents • be compatible with metals and other materials used in the manufacture of cable • non-corrosive to metals • resist deterioration when exposed to chemical pollutants and UV radiation. Transmission ANSI/TIA/EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology Distribution Company Page 10 of 35 The transmission requirements of connecting hardware used in the OSP shall comply with connecting hardware requirements of ANSI/TIA/EIA 568-B.2. It should be noted here that ANSI/TIA/EIA-B generally applies to the intra building components. However, these components are the same ones used to terminate and splice OSP cable. The testing performed on OSP cable is not subject to the same testing for the permanent link or channel tests of the intra building cable, unless the OSP cable is a category rated cable which is part of the loop being tested. An example may be a school having a portable classroom located within the 100 meter channel limitation that uses a category rated OSP cable to go from the main building to the portable. Terminal Block Requirements General Terminal blocks provide a means to connect service wire to distribution cable. Terminals are provided with a means for connecting each terminal pair to the distribution cable, and a means for connecting the service wire to the terminal block. OSP terminal blocks should be the insulation displacement contact (IDC) type, the most common being 110, just like the 110 block found in voice and data communications. Terminal blocks may be stubbed to provide conductors between the terminal block and connection point to the cable. They are typically housed in an enclosure designed to protect the terminal block from moisture and sun exposure. The following requirements apply to connecting hardware used as terminal blocks in OSP. Wire Compatibility, Pair Identification and Mounting Terminal blocks shall: • be compatible with the service wire used for an application. • have the recommended wire gauges for each block indicated by the manufacturer • shall meet electrical requirements for the smallest designated gauge conductor after connecting and disconnecting the largest designated gauge conductor • provide a means for identifying individual terminal pairs • provide a means for identifying the polarity of tip and ring of each pair • allow for fastening to a wood, steel or plastic backboard Test Points Terminal blocks shall allow access to test points for each pair without disconnecting the service wire from the terminal or puncturing the wire insulation. NOTE - High impedance probes are needed to use the test access points for live high frequency applications. Stub cable The stub cable shall use standard color coding to indicate individual pairs and tip and ring. Cross-Connect Block Requirements General Cross-connect blocks are used in OSP to connect feeder pair to distribution pair. Cross connect blocks may be located in cabinets, on walls or possibly even a rack designed [...]... the pipe Quang Dung Technology Distribution Company Page 27 of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant 90-Degree Sweep: a bend that exceeds the manufacturer's standard size 90-degree bend; (e.g., 610 mm [24 in] is standard for 102 mm [4 in] conduit) Back-to-back 90-degree Bend: any two (2) 90-degree bends placed closer together than 3 m (10 ft)' in a conduit run... of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant CONDUIT AND DUCT General Underground conduits are used to connect various access points along the underground route Examples of the access points may be a building, manhole, handhole, or splice point Conduit may be placed by: • • • Trenching Boring Plowing Conduit Type Conduit Type EB-20 EB-35 DB-60 DB-100 DB-120 Rigid... connect the cross-connect block to the distribution cable, the cable shall use standard color coding to indicate individual pairs and to indicate tip and ring polarity Optical Fiber Connectors Quang Dung Technology Distribution Company Page 11 of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Optical fiber connectors shall meet the requirements of ANSI /TIA/ EIA-568-B.3 The two... Special Tests Special tests for buried/underground/vault copper splice closures can be found in Bellcore documents TR-NWT-000014, TR-NWT-000251 and PUB 55004 Quang Dung Technology Distribution Company Page 18 of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant FIBER SPLICING Overview Splicing can be defined as the joining of two conductors or fibers together to restore... Distribution Company Page 19 of 35 ANSI /TIA/ EIA 758 • • • Telecommunication Cabling of Customer Owned Outside Plant store and organize the fibers and splices protect the fibers prevent the fibers from exceeding the minimum bend radius INDOOR SPLICING General Optical fiber inside terminals shall meet the requirements of the ANSI /TIA/ EIA-568B.3 standard This portion of the standard refers to and governs fiber... accumulation of water inside the closure Special Testing Quang Dung Technology Distribution Company Page 22 of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Special tests for free-breathing optical fiber splice closures can be found in Bellcore document GR-771-CORE Sealed Aerial Closures • • are similar to underground closures with aerial hanging hardware added are designed... Tests Special tests for direct-buried optical fiber splice closures can be found in Bellcore document GR-771-CORE Shield Isolation/Grounding Closure • provide an air tight/water tight protective enclosure for a optical fiber cable sheath opening Quang Dung Technology Distribution Company Page 23 of 35 ANSI /TIA/ EIA 758 • Telecommunication Cabling of Customer Owned Outside Plant The closures function only... Radius After Installation 8 10 Page 14 of 35 ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Exceeding the above bend radii may affect the performance of the system OSP Twisted-Pair Testing OSP twisted pair cables are not subject to the same tests as horizontal UTP cables are The primary field test parameters for OSP twisted-pair cabling are: • • • • • • • • DC loop resistance... 25 mm to 228 mm (1 in to 9 in) (or equivalent cross-sectional areas if not round) Quang Dung Technology Distribution Company Page 17 of 35 ANSI /TIA/ EIA 758 • • • • • Telecommunication Cabling of Customer Owned Outside Plant should have replacement and special application parts shall be readily available should avoid the use of specially-ordered non-catalog stock parts the encapsulant must not generate... Testing Special tests for aerial copper closures/terminals can be found in Bellcore document TR-NWT-00014 Buried Service Wire Closures • are used to join underground service wire Quang Dung Technology Distribution Company Page 16 of 35 ANSI /TIA/ EIA 758 • • Telecommunication Cabling of Customer Owned Outside Plant shall be compatible with the wires shall have a 40 year life span Application Buried service . Bellcore documents TR-NWT-000014, TR-NWT-000251 and PUB 55004. ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology. 73 3-2 470 Website: www.qd-tek.com.vn Email: info@qd-tek.com ANSI /TIA/ EIA 758 Telecommunication Cabling of Customer Owned Outside Plant Quang Dung Technology

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