Custom Search
|
|
|
||
 MIL-HDBK-1012/3
and external ringers should be located to provide overlapping
coverage. Since most warehouse facilities exceed 90 m (295 ft.)
in length, fiber optic connectivity to remote terminals located
in the warehouse is recommended. Small numbers of data
subscribers may be inexpensively extended beyond the 90 m
(295 ft.) restriction by applying individual UTP/fiber optic
transceivers to these drops.
1.4.1.11 Miscellaneous. Buildings not specifically covered
herein may be comprised of a combination of several building
types or they may be unique. When they are unique, the major
claimant shall be approached for distribution requirements.
1.5
Horizontal Pathways. Horizontal pathways are
structures used to protect, support, and conceal the horizontal
distribution cables which run from the workstations to the
serving telecommunications closets. The number of cables to be
run, their sizes, bend radii, cost, and construction design of
the building are all considerations in determining the pathway
type. More than one type may be used within a building. The
RCDD may or may not be afforded an input into the architectural
decision whether to run the horizontal pathways within the floor
or the ceiling structure but should review their number and size.
The design of the pathway must be documented in the construction
drawings to eliminate conflict with HVAC and electrical systems
also being installed in the same areas. It is imperative that
the RCDD properly size the horizontal pathway to support the
estimated building life and ensure that they are installed
properly to avoid EMI or congestion. Generally data cables from
the workstation jack are to be home run to the serving
telecommunications closet to comply with the EIA/TIA 568
restriction to two cross connect points. However, there may be
instances where the user population is so fluid as to require
frequent relocation and rewiring of workstations. This is common
in large areas populated with modular furniture. The cost of
rerunning these cables all the way back to the closet for each
relocation may be reduced by using a zone distribution to the
center of the area and coiling extra cable, not to exceed a total
length of 90 m (295 ft.) in the ceiling. Another option, while
not normally recommended, is to disregard the EIA/TIA 568
standard that allows only two cross connect points and install a
zone distribution cross connect point within the work area. The
zone distribution box would be permanently cabled from the
serving telecommunications closet and then extended by an
additional distribution cable to the workstation. Relocation of
the workstations or addition of a workstation would require that
a cable be pulled from the zone distribution box to the
workstation faceplate rather than from the closet to the
workstation.
23
|
 
|
|
|
||
