- The following technical article was current at the time it was published. However, due to changing technologies and standards updates, some of the information contained in this article may no longer be accurate or up to date.
The Keys to Horizontal Cabling Flexibility
Siemon's MAX® Zone Unit (ZU) Enclosure
For most corporations, workforce flexibility is a strategic asset in today's dynamic, highly competitive global economy. The ability to rapidly configure and deploy skill-specific, cross-functional teams enables companies to quickly take advantage of market opportunities or respond to competitive threats.
A flexible workforce requires a flexible workspace. Modular office layouts have become extremely popular because they are easy to reconfigure as the needs of an organization change. When teams or departments are reorganized, cubicle walls and furniture are frequently rearranged to meet new layout requirements.
But what about the network? Is there a way to install a structured cabling system that accommodates frequent moves, adds, and changes (MACs) without having to install new horizontal cables all the way back to the telecommunications room?
The answer is yes. By using consolidation points or Multi-User Telecommunications Outlet assemblies (MUTOAs), a system designer can provide a location within the horizontal pathway, close to the office space, that keeps reconfiguration of cabling close to the work area.
The ANSI/TIA/EIA-568-B.1 (‘568-B.1) Commercial Building Telecommuni-cations Cabling Standard defines a consolidation point as:
A location for interconnection between horizontal cables extending from building pathways and horizontal cables extending into furniture pathways.
The standard goes on to explain that only one consolidation point may be used within any horizontal cable run and that it should be at least 15m (49 ft) from the telecommunications room.
Siemon's ZU-2 Enclosure with S210® Block
In order to facilitate MACs, the consolidation point should be installed in an area that is easily accessible by technicians. Consolidation points are often located within a lockable enclosure, such as Siemon's CPEV (see pages 5.2-5.3 of the Siemon 2001 catalog). This enclosure is mounted to a column or a wall in proximity to the work area. The interconnection within these types of enclosures is typically accomplished by terminating the cables that extend from the telecommunications room to S110®(category 5e) or S210®(category 6) connecting blocks. Solid twisted pair cable is used between the consolidation point and the work area outlet. Typically, the consolidation point end of this cable is terminated with S110®or S210®field installable patch plugs while the work area end is terminated to the back of the work area outlet.
For category 6 installations, an S210® connecting block provides the flexibility of a consolidation point without sacrificing channel performance. With over 13dB of NEXT margin over category 6, the S210®block has virtually no impact on channel NEXT performance when used in a consolidation room. Perhaps that is why many in the industry refer to the S210®as the "stealth block".
In some cases, it is desirable to conceal the consolidation point above a suspended ceiling or below a raised floor in specifically designed zone unit enclosures. Space is often limited in these situations, especially in raised floor applications. Consequently, enclosures used for these applications have a lower profile and require use of modular outlets. To make the connection from the consolidation point to the work area, a single-ended modular cord (constructed with solid cable) is required. The modular plug is mated to the outlet in the consolidation point and the other end is terminated to the back of the outlet at the work area.
To insure category 5e or higher system performance, Siemon recommends the use of factory terminated and tested single ended modular cords, such as the IC5 (category 5e) or IC6 (category 6). Both of these cords are constructed with premium solid cable and have a high-performance, factory tested modular plug on one end.
Consolidation points are not limited to just twisted pair. The same time and cost saving advantages of copper consolidation points are available to customers who bring fiber to the desk.
Siemon's MAX® MUTOA
Another alternative for customers who frequently reconfigure workstations is the Multi-User Telecommuni- cations Outlet Assembly (MUTOA). A MUTOA is a mini-enclosure that can serve up to 12 work areas (see photo on left). Horizontal cable is brought into the MUTOA and terminated to the back of the work area outlets. Equipment cords are plugged into MUTOA outlets and run to equipment at the desk. Whenever possible equipment cords should be routed through modular furniture pathways to protect the cords.
Equipment cords used with MUTOAs may be longer than the maximum length of 5m (16 ft) used in a typical installation. The ‘568-B.1 standard allows for longer equipment cords when the horizontal cable run from the telecommunications room to the MUTOA is less than 90m (295 ft). The shorter the horizontal run, the longer the work area cord may be (see chart 1 for cord length options). For fiber, however, no reduction in the total channel length standard of 100m (328 ft) is required.
The key advantage of a MUTOA is that it provides a completely modular solution for work area changes. Since there is no horizontal cable to re-run, the office layout can be easily changed with minimum expense. It provides customers easy access and makes work area changes as simple as plugging an equipment cord into an outlet.
Copper work area cables connected to a MUTOA, shall meet the requirements of proposed ‘568-B.1. The maximum length of copper work area cables shall be determined according to:
C=(102-H)/1.2 W=C-5 (less than or equal to) 22m(71ft.)
Please note that since the MUTOA is considered a work area outlet, it should not be located in ceiling spaces or below raised floors since users need easy access to the outlet to manage work station equipment connections.
Many MUTOAs can be configured with fiber, copper, and/or other outlet types. The MUTOA also offers added flexibility by providing a storage area for fiber cable slack within the assembly. This allows the outlets to be changed or upgraded as the technology of the users' active equipment changes.
By using consolidation points and MUTOAs, organizations can install cabling systems that allow them to efficiently and cost effectively make moves, adds, and changes.