Fiber optic transmission and modern parking garages

Medium lends flexibility in design and implementation

As the population density increases and land becomes a scarce commodity, having open areas set aside solely for parking becomes increasingly difficult. As a result, the need for efficient parking garages becomes paramount. Anywhere large numbers of people congregate for work, business or recreation vehicles need to be accommodated.

As with all public facilities, personal security needs to be provided. The design of the parking garage lends itself to unique challenges in protecting the public. Parking garages by nature of their design have a mix of large open areas and small confined spaces. Surveillance, access control and emergency intercoms are critical to protection for the public.

Parking garages require multiple CCTV cameras strategically placed throughout the facility to provide surveillance. The inherent nature of this type of structure, distance between cameras and monitoring locations make fiber optic transmission the optimal transmission medium. Although other mediums such as wireless might be considered, the benefits to using optical fiber for this type of application are many. They include high bandwidth, longer distances, secure transmission and reliability.

In the recently completed parking center at the Jackson-Madison County General Hospital in Jackson, Tenn., optical fiber was chosen as the preferred medium. The eight-floor, 676-space garage was the first part of a five-phase hospital expansion. In addition to the garage, the project includes a five-story medical office building and a walkway that connects the parking garage and the main hospital. The parking garage CCTV system is part of an overall integrated security solution that SimplexGrinnell is providing to help protect life and property at the Jackson-Madison County General Hospital. The solution includes analog CCTV, access control and emergency telephones throughout the campus, as well as an advanced security command center and a comprehensive service agreement to keep the systems in top working order. Integrator SimplexGrinnell made the decision to use optical fiber throughout the entire facility.
SimplexGrinnell’s Joe Trowbridge was the project manager and he turned to Dave Downard of Vihon Associates of Tennessee to recommend a solution for their surveillance and monitoring challenges for the parking garage phase of the project.

That decision to use optical fiber as the transmission medium gave Vihon Associates many options on the type of surveillance system they could recommend for this phase of the project. Vihon Associates turned to ComNet Communication Networks, a fiber optic communications company, to design a solution based on the parameters of the project.

The central monitoring site would be located 2,500 feet from the termination room in the new parking complex. This distance was beyond the capability of coaxial cable and the decision to use fiber optic cabling became essential. The design specifiedby Simplex Grinnell called for installing 64 fixed cameras, 22 PTZ cameras and four high-resolution license plate cameras. All the CCTV surveillance signals were to be transmitted over 96 strands of multimode fiber between the garage termination room and the main hospital’s central monitoring location. The plan also called for the video to be monitored and controlled from the main security control center as well as three other locations: the security director’s office, the security coordinator’s office and the main CCTV termination room.

Video encoding schematics

One question that came about was whether to choose an Ethernet-based or some other video-encoding scheme that could be transmitted over optical fiber. Because of the decision to use optical fiber as the medium, this gave the designers the flexibility to use either encoding scheme. Optical fiber is an ideal medium for Ethernet, providing bandwidth, distance and noise immunity over other transmission media. One of the advantages of an Ethernet over optical fiber system is the ability to “network” all the video and security data, allowing numerous users to view and access the system from multiple locations throughout the facility simultaneously.

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