Communication Infrastructure Upgrade on Mauna Kea
Institute for Astronomy
The communications infrastructure on Mauna Kea is in need of upgrading
to provide adequate service to existing and planned facilities on
Mauna Kea, in particular Gemini and the Smithsonian Submillimeter
Array (SMA). The upgrade includes replacing the four fiber optic
cables currently serving CFHT, IRTF, Keck, and Subaru with a single
fiber sheath, replacing the GTE Hawaiian Tel Cu cable and adding a GTE
Hawaiian Tel fiber optic cable.
The improvements described in this
report affect Gemini, CFHT, IRTF, Keck, Subaru, SMA, JCMT, and CSO and
will focus on an effective use of the two 4-inch conduits running
between HH-16 near CFHT and HH-23 near Keck.
Currently there are two 4-inch communications conduits extending along
the northern route from the Summit Communications Room that serve
CFHT, IRTF, and Keck. CSO and JCMT are currently served along the
southern route. Four 4-inch conduits have been installed from HH-23
near Keck to HH-25 near Subaru. As part of the Gemini project, new
communications infrastructure consisting of four 4-inch conduits will
be laid between the Summit Communications Room and HH-16 near CFHT.
Currently, one of the conduits along the northern route contains a 200
pair GTE Hawaiian Tel Cu cable for telephone service and the other
conduit holds up to four fiber optic cables. The fiber optic cables
are currently used in the Summit Communications Network operated by
the Institute for Astronomy. Both of these conduits are congested
preventing any additional pull of cables without prior removal of
The basic communication requirements for each facility on Mauna Kea include
- GTE Hawaiian Tel Cu cables for telephone (voice) connection (25+
- GTE Hawaiian Tel fiber optic cables for high bandwidth wide area connection
- UH fiber optic cables for local area network around the summit and
Hale Pohaku (minimum 6 pairs of fibers/facility)
GTE Hawaiian Tel currently does not
have fiber optic access to any of the facilities.
The current plan calls for supplying the communication needs to
Gemini, CFHT, IRTF, Keck, Subaru, SMA, JCMT, and CSO through the
The project is expected to be completed in two
phases. The first phase comprises the infrastructure upgrade that the
Gemini Project has planned between the Summit Communications Room
(SCR) and CFHT. The second phase will commence once the conduits
between Subaru and CSO have been installed as part of the SMA
Phase I will include a replacement of the main fiber distribution
center in the SCR. The new rack with fiber optic distribution panels
will be chosen to accommodate future expansion of the network,
including any transitional work required. The existing fiber optic
distribution panels can and will be relocated to the new rack before
Gemini pulls in the new fiber sheath.
Gemini will pull a single new
fiber sheath containing at least 32 fibers through the new conduits
from the Summit Communications Room to HH-16 at CFHT. These fibers
will be field spliced to the existing MKOCN fibers leading to CFHT,
IRTF, Keck, and Subaru with the understanding that fibers currently in
use will not be cut until it has been confirmed that the new fibers
During Phase II, the four separate fiber optic cables (between CFHT
and Keck) and the fiber optic cable installed during Phase I serving
CFHT, IRTF, Keck, and Subaru will be replaced by a single sheath of
fiber optic cable containing up to 12/16 bundles of 6 pair fiber optic
cable (or 24/32 bundles of 3 pair fiber optic cable, depending on the
vendor) for a total of 144/192 fibers. The diameters of the 144 and
192 fiber cable are approximately 0.85" and 1" respectively.
Each of the 8 facilities (Gemini, CFHT, IRTF, Keck, Subaru, SMA, JCMT,
and CSO) will be allocated up to 12 pairs of fiber optic cables,
tripling their current capacity. The fiber optic cable will be field
spliced at hand holes near each facility to fibers leading to the
patch panels in each facility. The main fiber optic cable will
terminate near CSO with any unused fibers left un-terminated.
Hawaiian Tel will pull an additional bundle of fiber for its own use
and replace its 200 pair Cu cable at the same time.
conduit can hold either three 1 1/4" subducts or one 200 pair Cu
cable and two 1 1/4" subducts. The 72/96 pair fiber optic cable
will be pulled through a subduct. There are three possibilities for
using the two 4-inch conduits; which one is best requires further
analysis. The possibilities are:
- IfA fiber (f) in one conduit, and GTE fiber (F) and Cu cable (Cu)
in the other conduit. This option physically separates the UH and GTE
cables. This option prevents an upgrade of the Cu cable without
disrupting fiber optic based service offered by GTE.
- The IfA and GTE fiber share a conduit. The GTE Cu cable resides in
the other. The configuration allows for an upgrade of the Cu service
without interruption of fiber based services (currently favored).
- The IfA and GTE cables all share one conduit. leaving the second
conduit free for future expansion.
Proposed Implementation Procedure
- IfA replaces Summit Communications Room distribution panel.
- Gemini pulls one 32-fiber sheath from the SCR to HH-16 through
new conduit and splices pigtails to the fibers at the SCR distribution
- Gemini/HawTel pulls new Cu cable through the new conduit and
splices it to the existing Cu leading to CFHT, IRTF, Keck, and
- For each of the following facilities (CFHT, IRTF, and Keck),
- Identify the existing fiber bundle leading to the facility.
- Identify the currently unused fibers in the old sheath and field
splice those fibers to the new fibers.
- Test the newly spliced fibers.
- Splice the remaining fibers to the facility.
- IfA reestablishes the MKOCN.
- Gemini removes the four old fiber cables from the old conduit
between the SCR and HH-16.
Phase II (assuming Option 2 under 4.2)
- GTE Hawaiian Tel (HawTel) pulls permanent Cu cable (Cu-1) between
CSO and Keck through the new conduits and temporarily splices the
cable to the Cu cable (Cu-0) connecting the SCR and CSO.
- HawTel provides temporary service to Subaru and Keck through
- HawTel pulls out old Cu between Keck and IRTF.
- HawTel pulls in 3 subducts in conduit (A) between Keck and
- HawTel pulls in temporary 25 pair or less Cu cable (Cu-2) through
one of the subducts and splices it to Cu-1 to provide temporary
service to IRTF.
- HawTel removes old Cu trunk between CFHT and IRTF and pulls three
subducts into the empty conduit (A).
- HawTel pulls in new 72/96-pair MKOCN fiber and its own fiber from
Summit Communications Room to CSO through the subducts in conduit
- Fibers leading to the patch panels of CFHT, IRTF, and Keck/Subaru
will be spliced to the new (Phase II) MKOCN fiber sheath.
- The FDDI ring will be reconnected using the new fibers.
- The old MKOCN fiber optic cables will be removed from the Conduit
- The 32-fiber sheath installed during Phase I can be removed at
- HawTel will pull in the new Cu cable (Cu-3) from CFHT to Keck
though Conduit B.
- Temporary Cu service to IRTF, Keck, and Subaru will switch from
the temporary service, i.e. via Cu-1 and Cu-2, to Cu-3.
- HawTel removes temporary Cu (Cu-2) cable between Keck and IRTF.
- HawTel disconnect Cu-1 from Cu-0, and splices any remaining Cu-1
pairs to Cu-3 pairs at Keck.
Map of Area