Controlling airport access.
Construction of DIA began on September 27, 1989. The terminal building is a multistory, three-module structure of stone, masonry, steel, and glass providing four levels for passengers and tenants. A large central atrium covered by a stretched roof of Teflon-coated Fiberglass covers 376,332 square feet and allows natural light into most of the public areas. Shops and passenger services are located along the atrium. An underground automated guideway transit system (AGTS) links the terminal with the airside concourses.
An airport access control system requires giving many people access at different times and places. Baggage doors and airplane boarding gates are two examples of locations where authorized personnel, such as baggage handlers, caterers, and supply stockers, need to be able to enter. Security dictates that these areas not remain open to everyone at all times, so access times must be assigned on a per person/per portal basis. Management also wanted an anti-tailgating feature to be incorporated into the doors and vehicle gates to ensure that only one person passed through per card.
Another concern was that both the existing Loronix, Inc., photo image badging system and the IBM System 38, the airport's mainframe computer, had to be integrated into the new access control system. This was necessary to allow the airport's staff to manage personnel immediately and without having to reenter information. All the badging records and images are to be stored on the access system's file server.
Solutions. To meet the design challenges of such a large facility, Cardkey Systems, Inc., the system integrator, used distributed processing architecture. Such architecture allows the information from the central database to be sent out to and stored in the field computers and control panels, so that decisions on granting access and other aspects of security can be processed locally.
Intelligent device controllers (IDCs) in the field monitor and control airport terminal doors and airfield gates and communicate with the central computer. Each IDC stores up to 20,000 cardholders. These can be revised instantly at the central computer. Up to 10,000 transactions can be stored in an IDC until it has the opportunity to upload them to the central computer.
In addition, the IDC has the ability to control alarm input points and command specific output points, even during a communications failure. At DIA, one or two doors are controlled by an IDC. The IDC continually monitors the door alarm contact, the magnetic door lock, the photoelectric beam, gate controllers, help buttons, and enclosure tamper switches. During normal operation, the IDC uses the programs stored in its local memory to control these devices.
When a card is presented at the reader, the IDC checks its database to see if that card is allowed access through that door at that time. If allowed, the IDC automatically activates the output relay associated with that door's magnetic contact for the time period associated with that card at that door, and it shunts the door alarm contact for the same time period. If the individual keeps the door open longer than the time allotted, an alarm is generated and passed on to the area control computer (ACC). Additionally, the IDC monitors the photo beam located in the doorjamb and will pass an alarm to the ACC if more than one person attempts entry.
Other IDC functions include the monitoring of the help button, the tamper switch, and the door contact during noncard access time. The IDC monitors these devices and indicates a change in state when it occurs and passes its finding on to the ACC. The IDC will also complete any local actions that are necessary, such as sounding a local alarm at the door if the door's alarm contact is activated when a door is forced open.
Since the facility is so large, information processing time was a major concern. To speed up the processing time, peer-to-peer networking was installed. This allows the IDCs to communicate with each other without involving the central computer.
The owner's requirement to use fiber optics led the installers to choose a star network, which fans out through fiber-optic couplers, to connect up to twenty-two of the IDCs. They are set up in a fault-tolerant configuration to ensure that any data line failure would only affect the IDCs on that line. Continuous communication checks allow the system to adapt to failures, and continuous diagnostics permit the type and location of failures to be annunciated at the central computer. Since the facility is so large, RS-485 multidrop and fiber-optic networks were used; they cover distances of up to 10,000 feet.
To make it easier to interface system functions, a host access control computer was chosen that used a standard base operating system, IBM's OS/2. That approach allowed the system integrator to purchase off-the-shelf software to connect the photo-imaging system to the main database.
CCTV. The CCTV system uses an American Dynamics matrix switcher capable of handling 2,096 cameras and 256 monitors. When the facility opens, the system will make use of more than 750 cameras, 2 of which will be forward-looking infrared cameras (FLIRs). FLIRs are no-light cameras that view the infrared energy emitted from an object. In this application, they will provide perimeter security and Federal Aviation Administration (FAA) aircraft viewing during limited or zero visibility conditions.
The system is configured with one central alarm receiving location and twenty-five remote controlling locations for continuous monitoring. The CCTV system is connected by an ASCII interface to the card access system. Within one second of an alarm, the local IDC transmits the condition to the central alarm workstation. From there the system automatically calls up the camera located at the alarm location, if applicable, and a picture of the scene appears on a monitor. The operator at the alarm workstation will then select the alarm from the alarm queue on the access control workstation and act on the alarm.
The CCTV processor also connects the audio from the scene, if applicable, to any monitor in which the alarm camera is viewed, as well as to the corresponding VCR. All of this interfacing is transparent to the operator, and no special functions must be completed for them to be carried out.
Badging system. The photo-image badging system includes solid-state cameras, tripods, color printers, a badging workstation, laminator, and a magnetic stripe encoder. This is where people are entered into the system, given an authorization level, and made part of the network's database. The deauthorization of an access card is only to be performed at the central computer by security personnel. The database for the badging system is stored on the new file server, which was provided with the card access system, to reduce the need for additional computers and components.
Audio intercoms. When an alarm sounds anywhere in the airport, it will go through the audio intercom subsystem, comprised of central switching components, including a programmable logic controller (PLC) and custom-designed audio relay cards. The audio relay cards, commanded by the PLC, direct the audio from the field microphone/speakers to the appropriate VCR for recording or to the main alarm monitoring station for two-way communication.
The connection of a remote station and central control occurs automatically on any alarm condition in the area of a station, this switching requires no operator action, and the audio is recorded on the appropriate video recorder along with the video camera's image.
This subsystem uses both integrated and interfaced network connections. The audio to and from the remote station is integrated with the video into the fiber-optic backbone and modem, while the PLC is interfaced to the CCTV system's matrix switcher through an ASCII connection. Audio follows video, whether the camera is selected because of an alarm condition, which is transmitted from the card access system, or through the matrix switcher's central keyboard.
Doors. Twenty-five different types of doors, including roll-up doors and vehicle gates, required card access. Each door type is configured to accommodate the specific security requirements of that type of portal. Swing doors accessing the air operations area (AOA), for example, have a card reader located on the exterior side of the door, with the IDC for the door located on the interior side with a reader and a help button incorporated into its enclosure.
The help button is to be used if the person requesting access has any problems getting through the portal. Depressing the button will annunciate an alarm at the alarm workstation, and the CCTV/intercom for that location will be automatically displayed.
Since the facility includes hundreds of swing doors, anti-tailgating on all swing doors was important. Electronic eyes were installed in the doorjambs to monitor the number of people passing through. The IDC is programmed to alarm at the central station should more than one person attempt entry. If the time allowed to progress through the door, which is stored in the IDC, is exceeded, an alarm is transmitted to the alarm workstation.
Vehicle gates are interfaced with the access control system through the use of automatic gate controllers. Each gate is monitored by the IDC and the central computer to see whether it is opened or closed and to determine vehicle position. The IDC also controls its sequence of operation for both vehicle and pedestrian passage.
Fire alarm. The building's fire alarm system, made by Edwards System Technology, is both integrated and interfaced into the security system on a door-by-door basis. Each fire egress door will automatically release when there is a fire, as required by local building codes. In addition to the required interfaces at the doors, the fire alarm system is integrated into the card access system via an ASCII connection.
Like the access control system, the fire alarm system uses distributed processing panels that can operate independent of the host computer. Analog smoke and heat detectors are capable of having their sensitivity levels read by the panels and reported on a per point basis.
Each fire-initiating device (smoke, heat, pull stations) can pinpoint its exact location since each is individually addressed with its own unique number. Because of the enormous size of this complex, fire alarm speakers and strobes are zoned into selectable evacuation areas. Fire fighters can select which zones to include in a fire alert evacuation situation.
Implementation. A well-designed and carefully selected product can quickly become a nightmare if the installation, start-up, and contracting is not properly managed. An experienced, well-trained team of project personnel is the key to the success of installation.
Because of the overall size and complexity of the airport project, two project managers were assigned--one responsible for the card access system and another responsible for the CCTV and audio systems. The two managers worked together to coordinate all aspects of their portions of the project, from quality control to safety for themselves, their subcontractors, and the vendors. They were also a part of the airport's project management team, which was responsible for almost $3 billion in contracts.
A quality control engineer was assigned to ensure that all aspects of the project met with the standards outlined by the airport. All the contractor's employees at the site also participated in a corporate-wide Philip Crosby Quality Improvement program, which is an independent quality education program. Monthly meetings were held with DIA operations personnel, the software team, and project managers to discuss each stage of implementation.
Maintenance and ongoing service of this system was the final and most important element considered. A system that is too complex to troubleshoot will quickly become an expensive system to maintain. The DIA contracts required that a two-year comprehensive warranty be included with the system.
The design used at DIA has lent itself to easy maintenance because most doors have all of the control electronics located locally, requiring only one person in the field to perform tests and troubleshoot. The maintenance personnel at both Stapleton Airport and DIA have been trained in the maintenance of all the systems, and the facilities are certified as warranty repair depots.
After eighteen months and more than 50,000 hours of labor, DIA has its access control system. Striving to protect the millions of passengers who will visit the airport and keep its perfect track record with the FAA, DIA is ready to begin calling flights.
Robert B. Howard, EE (electrical engineer), and Donald M. Rochon, CPP, SET (senior engineering technologist-fire alarm), CDT (certified document technologist), are business development managers with Cardkey's Integrated Systems Group in Simi Valley, California.
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|Title Annotation:||Transportation Security; airport security systems|
|Author:||Howard, Robert B.; Rochon, Donald M.|
|Date:||Nov 1, 1993|
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