POF in international cabling standards
By Dave Hess
A revised version of IEC 60793-2-40 (“Sectional Specification for Category A4 Multimode Fibres”) containing four new high-performance plastic optical fibers (POFs) was published in March (see Standards Watch, Lightwave, May 2006, page 12). With companion cable standards incorporating these fibers developed by IEC SC86A/WG3 already passing initial ballot, the stage is now set for the new fibers to become fully integrated into the LAN cabling technology standardization portfolio.
ISO/IEC JTC1/SC25 (International Standards Organization/International Electrotechnical Commission Joint Technical Committee) is writing the first international cabling standard that includes transmission channel types constructed using these new fibers. Derived from the original ISO/IEC 11801, “Generic Cabling for Customer Premises,” ISO/IEC 24702, “Generic Cabling for Industrial Premises,” is the first in a new series of cabling standards. The document is being prepared for final ballot and is expected to be published this year.
The new industrial cabling standard includes specifications for channel performance, such as attenuation, bandwidth, distance limits, and connector specification references. The older large-core POF operating at a 650-nm transmission wavelength can be used to construct channel classes having 25- or 50-m distances. The newer POF, operating at 650, 850, or 1300 nm, or plastic-clad silica fiber operating at 850 or 1300 nm can achieve considerably longer distances of 100 and 200 m.
In contrast to ISO/IEC 11801, the main purpose of ISO/IEC 24702 is to introduce a new regimen of environmental specifications. In addition to the harsher ambient conditions in an industrial (factory) setting, ISO/IEC 24702 has new specifications for ruggedness, such as flexibility, that are relevant for POF. This flexibility, together with simpler termination, is driving new interest in POF for other LAN applications. With the establishment of POF into industrial cabling standards by ISO/IEC 24702, POF also is expected to be incorporated into cabling standards for residences (homes), data centers, and commercial buildings (offices).
Dave Hess is technical manager for standardization with Nexans Data Communications Competence Center (www.nexans.com). He has contributed to regional and international standards committees for more than 15 years and has participated throughout the development of TIA-568 and ISO/IEC 11801 series cabling standards. He can be reached at email@example.com.