Fiber Optics Lights a Path to Success

Fiber-optic network helps Montefiore Medical Center remain leader in health care field.Montefiore Medical Center (MMC), New York City, knows the challenges of designing and installing a robust network communications system firsthand. Through a hospital-wide re-engineering project, MMC deployed an advanced fiber-optic network to connect every site in its network, including doctors' offices, affiliated

Fiber-optic network helps Montefiore Medical Center remain leader in health care field.

Montefiore Medical Center (MMC), New York City, knows the challenges of designing and installing a robust network communications system firsthand. Through a hospital-wide re-engineering project, MMC deployed an advanced fiber-optic network to connect every site in its network, including doctors' offices, affiliated hospitals, and ambulatory care centers. Fiber-optic cable (small in cross section, lightweight, electrically isolating, non-radiating, and offering high bandwidth) proved an ideal solution in creating a "macro" communications network solution.

The $42-million communications upgrade was completed in three phases:

Phase 1. Fast track deployment of fiber hubs. Network "backbones" form loops that begin and end in the hospital's network communications center (NCC). Within a loop, six or 12 fiber-optic strands are terminated in each direction in selected hub rooms, to provide a diverse redundant system. In critical areas, the hubs use "live" fiber from each direction to provide "hot" standby in case of a failure or a fiber break.

Phase 2. Infrastructure rollout. Three Cat. 5 cables serve each desk location; two of the cables are devoted to data circuits and one cable to a voice/data circuit. Each department's budget as well as individual or group needs determined circuit locations.

Phase 3. Connecting the entire MMC community. The fiber-optic ring also connects adjacent facilities and offsite locations. While work progressed on Phases 1 and 2, synchronous optical network (SONET) rings (see sidebar, on the original article's page 64LL) were called upon to connect the entire network to affiliated hospitals and outpatient facilities throughout the Bronx.

Campus layout. A 12-fiber "micro" network already connected several buildings at MMC's campus, consisting of 16 separate but interconnected structures of various ages in a three-city-block. Over time, additional buildings, including a parking garage and a series of row houses, located on the east, south, and west sides of the campus, have become part of the hospital complex. Many of these are wired with fiber-optic cabling and copper wire cabling for voice services.

The use of aerial cable helped extend the fiber-optic backbone from the main building to some buildings south of the campus, since running cables underground was cost prohibitive. Outdoor-rated fiber-optic cable has a loose buffer tube type of construction to permit thermal contraction and expansion. A Kevlar yarn or steel strength member is part of the installation to support wire stringing operations and mounting. A gel filling within the cable keeps moisture away from the fibers and minimizes moisture flow down the cable core, thus protecting the electronic equipment at either end of the cable.

Network design. The fiber-optic backbone consists of cables with 96, 60, 48, or 24 strands of multimode fiber, depending on the capacity needs of each building. As many of the buildings are behind the main hospital, a star topology design was selected to interconnect all users. Smaller groups of buildings form clusters. A collapse point is within each cluster, serving as an interconnect to the NCC. From this point, the fiber connects to the NCC through a 100BASE FL switch or is directly tied to the fiber switch via patch cords (Photo 1, on the original article's page 64FF).

The cables and administrative hardware consist of:

• Riser cables that run vertically through the building core, terminating at designated administrative distribution closets (Photo 2, on the original article's page 64FF). The cables eventually route back to the originating point to provide system redundancy.

• Horizontal plenum-rated, fiber-optic cables that provide connectivity to existing hubs or departmental "micro" networks.

• Work area cables (horizontal link) run from the work area wall plate to patch panels in the hub room. These are typically 4-pair, Cat. 5, unshielded twisted pair (UTP) copper cables. In work areas too far from a communications closet, installers used fiber-optic cable.

Hub deployment was simplified by making hundreds of fusion splices at strategic transition locations, rather than at the NCC.

One of the most challenging aspects of the design involved gaining adequate closet space for the new equipment. Space is at a premium and was not easily relinquished by individual departments. Usually, a straight riser path was not possible. Conduit bends as well as transition and mounting hardware supports the fiber-optic cable. The communications closets; or in some cases, lockable cabinets; hold the racks, patch panels, electronic hubs and conversion equipment, with the uninterruptible power supply (UPS) equipment (Photo 3).

Standards and testing. As is typical in the telecommunications industry today, the installation complies with the latest TIA/EIA standard regarding cabling. The standard provides guidelines on issues such as bend radius and distance limitations. MMC chose to standardize on the products of a major cable manufacturer and on the use of Type SC connectors. The 568SC duplex connector is widely recognized as the standard fiber-optic interface at the wall outlet in premise applications. Defined in the TIA/EIA 568A Commercial Building Telecom Standard, the SC connector offers power coupling efficiency and repeatability in disconnecting and repositioning the connector. After the fiber-optic cable was installed, each fiber was tested in accord with TIA/EIA 526-14, Optical Power Loss Measurements on Installed Multi-mode Fiber Plant using Power Meters (Photo 4, on the original article's page 64LL).

Installation issues. The fiber-optic ring network was installed in incremental steps. Much of the work was accomplished during nights and weekends. E-J Communication Systems, a division of E-J Electric Installation Co., Long Island City, N.Y., was the electrical contractor working under the direction of project managers Gerry Curreri and Steven Caltabiano. The telecom network design team for MMC included Brian Hoch, Jim Fiorato, and Phil Munvez.

Facilities personnel in hospitals are continually challenged to design and specify robust communications networks. The fiber-optic system and network software installed at MMC will help this group remain a leader in the health care field. Patient registration, admissions, discharges, and the reporting of laboratory and radiology results are electronically processed through the system. These protocols help to reduce costs by eliminating duplication and reducing paperwork.

Sidebar: What is a Synchronous Optical Network?

ONET (synchronous optical network) is a telecom standard that allows data to be transmitted at speeds from 51.84 Megabits/sec (the basic rate) to as high as 9.6 Gigabits/sec. Among SONET's features is its support for self-healing rings, which permits a network fault to be circumvented by reversing the traffic flow. Survivability is further assisted by drop and repeat, a SONET capability that allows signals passed down the network to be terminated at one node and duplicated (repeated) before going to subsequent nodes. In matched node configurations of interconnected rings, drop and repeat allows a signal blocked by a fault to find an alternate path to its destination node.

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