Focusing on the theme "Exploring Global Perspectives," this year's BICSI show highlights everything from new products to DSL to UTP to licensing standards and regulations.
More than 2400 people showed up to see products from 130 telecommunications suppliers at the BICSI Winter Conference held in Orlando from January 19 to 22.
Mike Kincaid, Bellcore Learning Services, Lisle, Ill., discussed the opportunities and limits of Digital Subscriber Line (DSL) in a technical seminar. A hot-topic technology, DSL is nevertheless still slow enough to make a plain old telephone service (POTS) twisted-pair copper voice circuit look like a speedy high-bandwidth medium. Flexible bandwidth with a low entry cost is the driving idea behind the emerging multispeed DSL technologies.
The most likely adopters of DSL are users who want LAN-like performance with more bandwidth than a dial-up phone line can offer, but at speeds slower than T-1. These market segments include remote branch offices exchanging information with a corporate site; small offices independently linking to the Internet; partners and suppliers; and home office workers accessing e-mail, the web, and other networking services.
Licensing requirements A seminar on state licensing requirements for telecommunications installers proved to be another hot topic. The seminar's panelists brought attendees up to date on telecom legislation (either passed or pending) in various states.
Presently, only 10 states have existing legislation regulating who can provide cabling systems, according to BICSI's directory, "Existing State Licensing Legislation Governing Certain Professions and Occupations Affecting the Telecommunications Industry." The directory lists each state and indicates whether the laws of that state provide for licensing of telecommunications workers, electricians, electrical contractors, and professional engineers.
Each entry references which laws, if any, apply to each of the four professions. Each entry also indicates whether the state uses the NEC, and what party or parties are responsible for enforcing licensing laws. For a complete directory listing, see the BICSI web site at www.bicsi.org. Even though the directory pages for individual states do not show existing state statues, several cities and counties have enacted local ordinances requiring certain types of permits, licenses, or examinations.
Raceway fill rates Sheri Dahlke, American Polywater Corp., Stillwater, Minn., reported on recently completed tests on pulling single and multiple cables through conduits at fill rates between 30% and 90%. Based on the work done, it seems reasonable to set cable fill maximums based on a clearance of 20% of the conduit diameter. For example, the maximum-fill for systems with more than six cables would be in the 65% range. The TIA/EIA standards-making body is currently addressing the fill capacity for surface raceways. The 40% fill capacity is a conservative number, and the new TIA/EIA proposal is to increase that to 60%.
The idea is to design for 40% and leave the remaining 20% segment for moves, adds, and changes. A panel moderated by Robert Jensen, dbi, Austin, Texas, discussed additional UTP cabling parameters that will be published as an interim standard by the TIA. Jensen highlighted the impact on applications using parallel transmission schemes, such as 1000 Base-T (Gigabit Ethernet).
High-performance cables Not surprisingly, wiring vendors are promoting the need for high-performance cables because many users have started to implement Gigabit Ethernet. Level 7 cable, developed by Anixter Inc., is specified at twice the bandwidth of today's Category 5 cabling and achieves a 10-decibel attenuation-to-cross talk ratio (ACR) at 200 MHz. Its higher ACR delivers more usable bandwidth. It allows poor installation practices because it is more difficult to deform twist relationships between the pairs internally due to the bonding of the pairs and molding of the jacket.
Members of the panel included Masood Shariff, Bell Labs of Lucent Technologies, Middletown, N.J.; Terry Cobb, consultant, Everett, Wash.; Paul Kish, NORDX/CDT, Quebec, Canada; Henriecus Koeman, Fluke Corp., Everett, Wash.; Paul Vanderlaan, Belden Wire & Cable, Richmond, Ind.; and Ned Sigmon, AMP Inc., Winston-Salem, N.C.
Media conversion myths The "top 10 myths of media conversion" covered two classes of network conversion: media conversion (such as a change from coaxial cable to UTP cable) and rate conversion (a change from one bit rate to another, such as from 10 Mbps Ethernet to 100 Mbps Fast Ethernet).
Stephen Anderson and Stephen Stange of Transition Networks Minneapolis, Minn., were able to lay to rest commonly held, but erroneous, views on cabling technology. Increasing network complexity requires intelligent solutions using media conversion. For example, a fiber-optic media converter can reliably and inexpensively extend the distance between two 10 BASE2 coax devices or two 10 BASE-T devices (using twisted pair wiring) up to 2000 m. You can perform this function without the additional expense of a repeater.
Cabling support systems Since the design and installation of proper support systems is more critical than ever, Ray Keden, Erico Inc., Solon, Ohio, showed the latest horizontal cabling support systems and fastening techniques to use when placing high bandwidth cables in a building. He noted that improper installation, crimped cables, or a tight bend radius all can jeopardize the integrity of a data networking system when it is eventually revved up to high speeds.
The speaker also mentioned the 1997 TIA/EIA-569-A standard revision now allows the installation of appropriate cable fasteners on suspended ceiling support rods or wires, which may carry multiple cables. Also, you can use the T-bar rail of a suspended ceiling to mount appropriate cable fasteners loaded with up to 16 four-pair 24 AWG UTP cables or equivalent. In any case, the cables have to be at least 3 in. above the ceiling for easy lifting of the ceiling tile.