Open Office Cabling Practices

Cabling problems associated with open-office furniture have been building up for some time--in fact, ever since the first terminal was moved from the mainframe into the office. To address these problems, the Telecommunications Industry Association has formed an Open Office Cabling Task Group to consider changes in the standards that will impact this area. Some of the issues the task group is studying include:

George Weller, Steelcase

Cabling problems associated with open-office furniture have been building up for some time--in fact, ever since the first terminal was moved from the mainframe into the office. To address these problems, the Telecommunications Industry Association has formed an Open Office Cabling Task Group to consider changes in the standards that will impact this area. Some of the issues the task group is studying include:

Cost of reconfiguration--Some organizations move their office furniture at least every six months. Often, voice and data cabling is cut where it enters the modular furniture. The cabling in the furniture is discarded, and cabling in the adjacent floor or ceiling is left in place, so that pathways eventually fill up. This is costly and wasteful.

It would be beneficial if we could instead unplug the furniture from the building, move it as needed and then plug it back in at a different point. A scheme like this, involving a consolidation point, is being considered. Another approach is to collect all the outlets in one place and then run long equipment jumpers through the furniture. This approach, which is also under consideration, uses the multi-user outlet. These practices are governed by TIA`s 568 standard.

Cable routing and termination--Pathway capacity and outlet/connector mounting space for open office furniture are frequently too small to accommodate the required cable and connector densities. These pathway and space problems, governed by the TIA-569 standard, are being studied. Standard minimum pathway capacities and outlet opening spaces have been proposed.

Noise--Such networks as the 100-megabit-per-second Fast Ethernet operate at higher speeds and lower signal voltages than has been the case in the past. Such networks may require new cable plant designs, especially when using Category 5 unshielded twisted-pair cable. Many open office furniture users have been asking whether or not electrical noise from power systems in the furniture will interfere with the operation of the new networks and make them unreliable. A Pathway Separation Task Group has been formed to address this complex question.

A revised TIA-569 pathways and spaces standard that incorporates the work of these task groups will probably be issued in 1995. A revised TIA-568 standard has just been approved by industry ballot, so changes in this area that affect it will most likely be published separately.

George Weller is a research engineer at Steelcase (Grand Rapids, MI), which manufactures office furniture systems. He is also chair of the TIA`s Open Office Cabling Task Group.

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