Phase 2: Design/
Planning Phase
The cabling plant design phase
must be able to “fit-for-purpose”
the ICT requirements as specified
in the program/pre-design stage.
The culture of
maintaining open
and informative
communication
with all stakeholders
of the commissioning
team members is
essential to meeting
the project’s
objectives.
14 I ICT TODAY
The first step in this second phase is an architectural review of the
campus, buildings, service entries, and the “white space” room. Focus is
on the ICT cabling infrastructure design considerations and identifying any
issues and concerns. Specifically, is there security and redundancy in the
pathways? Does the cables’ jacketing comply with environmental
conditions, local codes and best practice industry standards?
Will there be an inter-building cable run through manholes between
buildings for outside plant (OSP) pathways into the building’s fiber
equipment room (FER) or main point of entry (MPOE) or point of
penetration (POP)? Accordingly, the cabling must be OSP-rated and have
its own dedicated (not shared), secured, and redundant conduit pathways.
Data center room pathways are commonly routed in a hierarchical fashion
as follows:
• The meet me room (MMR) is where the service providers house their
equipment and cable connectivity to the outside world.
• From the MMR, direct underfloor/underground 4” conduits, as well
as overhead pathways (tray and conduit), are routed to the multiple
points of entry (POEs).
• In turn, each of these POEs has a mesh redundancy pathway routed
to each POD.
Who will have access to the conduits and the more susceptible overhead
pathways? Are the cable runs redundant as to not share the same pathway(s)?
Will it require conduit or armored cable between the POEs and POD(s)?
Always assume that water will migrate into underground conduits, even
within innerduct. Consequently, this intra-building cable should also have
an indoor-outdoor (I/O) rating, or it should be armored. Be cautious as raised
floors may also be classified as a plenum environment.
Another critical aspect in this phase of design is choosing when it is
practical to specify preterminated versus hybrid cable assemblies both for
optical fiber and copper. Successively, the design parameters and proper
testing of interfacing the two with field terminations should be addressed
for QA considerations.