By Patrick McLaughlin
The Telecommunications Industry Association (TIA) TR-42.1 Engineering Committee on Premises Telecommunications Infrastructure is in the late stages of revising its ANSI/TIA-758 standard covering customer-owned outside plant (CO-OSP) cabling systems. The finished product will be the “C” revision of that standard. When the committee began the revision process in 2018, it explained the standard “establishes the recommendations and requirements used in the design of the telecommunications pathways and spaces, and the cabling installed between buildings or points in a customer-owned campus environment.”
Once that standard is completed, designers and installers of CO-OSP systems likely will use it along with other published materials related to OSP cabling, including BICSI’s Outside Plant Design Reference Manual, published in 2018, and BICSI’s standard G1-17 ICT Outside Plant Construction and Installation: General Practices. That standard is regularly updated as methods and information related to OSP projects evolve.
“BICSI G1 is designed to provide general information relevant to all OSP construction and pathways, with additional standards under development providing in-depth detail on the specific pathways and associated tasks,” BICSI says. “Given the nature of development, this standard has been placed under continuous revision, so that as additional material is developed and approved, content within this standard can be modified to expand areas not present, or remove conflicts if they arise.”
BICSI offers a combination print and download of the standard for $10 to members and non-members. The downloadable version on its own is available to members and nonmembers at no cost.
Cable and connectivity products deployed in outside-plant networks possess physical characteristics that enable them to withstand the elements. In an interview, Siemon Company’s Janet Thomas, product manager for ruggedized connectivity, and Susan Cocco, product manager for the company’s copper product line, discussed some of the company’s harsh-environment products as well as product characteristics in general.
We asked Thomas what physical characteristics of connectivity products enable them to stand up to harsh environments, including outside-plant environments as well as industrial/manufacturing plants and other unforgiving spaces. “Siemon’s ruggedized copper and fiber plugs and outlets provide an IP66/IP67-rated seal, protecting plug and outlet contacts from dust, moisture, industrial cleaning chemicals and vibration,” she said. “Ruggedized copper cable assemblies are made with thermoplastic elastomer and polyurethane jacket types to offer better strength, temperature flexibility and resistance to tearing, abrasion, chemicals and moisture.
“Ruggedized fiber products are immune to electromagnetic interference [EMI] and radio-frequency interference [RFI], making them ideal for noisy environments,” Thomas continued. “Stainless steel faceplates provide corrosion resistance over their plastic counterparts, and ensure a protective seal against moisture and debris. Our line of ruggedized cable and connectivity solutions are ideal for protecting valuable connections in laboratories, hospitals, food-processing plants and other harsh environments.”
Siemon’s Cocco addressed the characteristics of a cable found in an OSP network: “OSP copper cable is suitable for direct-burial, lashed aerial, duct, and underground conduit installations,” she explained. “For example, Siemon’s Category 6A F/UTP OSP has four copper pairs segregated by a separator and wrapped in an aluminum foil shield for superior RFI and EMI protection. The cable jacket is filled with a non-conductive water-blocking gel to prevent moisture ingress, and this is all housed with a rugged UV-resistant outer jacket made of polyethylene.”
In addition to the BICSI and TIA standards mentioned earlier, the Insulated Cable Engineers Association (ICEA) has published a standard specific to OSP cable, Thomas and Cocco pointed out. “ICEA-107-2012 covers material, mechanical and electrical requirements for broadband buried service wire [BB-BSW],” they said. “Other standards include ISO/IEC 11801-1, ANSI/TIA-568.2-D, IEC 61156-5, UL 444, RoHS and REACH. Category 6A F/UTP OSP cable is designed to support the latest applications in outside wet environments.”
The ICEA also offers a standard for indoor/outdoor cable. ANSI/ICEA S-100-685 Standard for Thermoplastic Insulated and Jacketed Telecommunications Wire for Indoor/Outdoor Use was published in 2016. The standard’s purpose is “to establish generic technical requirements that may be referenced by individual telecommunications wire specifications covering thermoplastic insulated and jacketed wire products for indoor/outdoor application.” The standard further states that it is not meant to be used as a single document for procuring product. Rather, as stated directly in the standard, it is meant to be used in conjunction with an individual product specification that provides complete design details for the specific wire type and designates the applicable performance requirements.
Belden’s technology and applications manager for enterprise networks, Ron Tellas, explains some of the advantages of using an indoor/outdoor cable versus a cable used only for OSP networks. “Usually, OSP cabling extends between separate structures,” Tellas says. “The National Fire Protection Association (NFPA) requires that unlisted OSP cabling be terminated within 15 meters from its point of entry into a building, either through a wall or through the flooring. At this termination, the structured cabling transitions to listed cabling and continues to connect the enterprise network. A listed cable is one that is certified by UL for specific flammability ratings and listed for its intended use: usually CM, CMR or CMX. A listed OSP cable can extend beyond the 15-meter/50-foot limitation, and can also be used within enterprise buildings in other applications where the characteristics of OSP cabling are of great benefit.”
Some indoor/outdoor cables also carry a plenum rating, meaning they can be installed inside a building’s air-handling spaces. Several fiber-optic cables have this capability. AFL’s Indoor/Outdoor Plenum Distribution Cable is one. The company says these cables “are specified for campus network cabling between buildings where interbuilding lengths are short enough that the installer can recognize savings from the lower costs of terminating tight-buffered cables. For indoor applications, the cable is OFNP listed. For outdoor applications, the cable is manufactured with an outer jacket that incorporates a UV stabilizer for protection against exposure to the sun plus an anti-fungus protection for use in underground applications.”
On the copper-cable side of things, Hitachi Cable America (HCA) produces a twisted-pair indoor/outdoor-plenum rated cable called Drybit. The company describes a scenario for which this cable is a worthwhile solution. “Conduit that originates indoors but passes through or under a concrete slab is often subject to water infiltration. Standard plenum or riser-rated cable can’t be used in these situations since water will have a catastrophic effect on both their electrical and physical performance. The typical solution has been to use outdoor cable in the conduit, and then transition to the appropriately rated cable type once indoors.”
HCA introduced Drybit in 2018, describing the cable as one that can withstand the harsh conditions of a wet environment without suffering degraded electrical performance. “Drybit is verified by UL for long-term water submersion,” the company said.
In 2019 HCA released a Category 6A version. “Drybit Category 6A plenum-rated cable has enhanced electrical performance necessary to support 10 Gigabit Ethernet,” the company said.
The Category 6A version of Drybit is available in shielded and unshielded constructions.
Standards and standard-compliant products can produce a reliable outside-plant network cabling system..
Patrick McLaughlin is our chief editor.