Planning is critical for all electronic security systems, but it is most important for high-security applications that must comply with special requirements - which describes many government facilities. Requirements handed down by the government or code requirements make the funding for an electronic security system easier to obtain, but often those requirements make the electronics more complex and sophisticated.
Each classified government area has a specific level of security it must meet - the higher the level of classification, the more stringent the requirements become. Each level of classification will not be specifically addressed here - instead the focus will be on typical concerns and issues for electronic security systems in a government setting that can be resolved with a solid, well-thought-out plan to meet a given set of requirements.
High-security, government-classified areas must typically incorporate the following requirements:
- Sound emission control;
- Limited access;
- Documentation of personnel movement; and
- Detection of unauthorized access.
There is not a single solution that works in every application, but various approaches can be used to ensure the desired results. Since each classified area is unique, so too will be the electronic security system for that specific installation.
Security-in-Depth is an official designation that a given facility's security program consists of layered and complementary security controls sufficient to deter and detect unauthorized entry and movement within the facility. Examples include the use of perimeter fences, employee and visitor access controls, use of an intrusion detection system, random guard patrols throughout the facility during non-working and working hours, and closed circuit video monitoring or other safeguards that mitigate the vulnerability of unalarmed storage areas and security storage cabinets during non-working hours.
This layered approach is sometimes referred to as the "onion" design. As you peel away the various layers of the onion you get closer and closer to the center.
The layers usually start at the property line. The first layer of security starts at the site perimeter. Security measures here typically include access control - which would encompass a fence that must comply with certain standards, gates for vehicles and pedestrians, etc. The buildings typically have limited access, which is controlled by an electronic access control system, and/or security personnel.
Video surveillance measures should also be deployed, monitoring traffic, vehicle license plates, even the perimeter of the facility and visitor/employee faces. Cameras should be running at all times, and they must be properly placed to ensure operation in various light levels and the desired field-of-view. They should be strategically placed to view the various entrances and critical areas, such as docks, power substations, etc.
The second layer is added around the interior of the facility. A third layer might be at various areas inside the building. There may even be more layers of security - if the buildings contain highly classified security areas that contain compartmentalized, higher-security space within them.
Controlling Sound Emissions
Sound emissions refer to the ability to stand outside the classified area and be able to hear what is being said within the classified area.
The actual requirement will state a certain decibel level (db) that sound within the area must be attenuated. The scale uses a base-10 logarithmic scale, similar to the Richter scale for earthquakes. Each number change on the Richter scale means that the earthquake is ten times as strong. On the db scale, every 3db reduction is 1/2 the power or sound level.
A typical security requirement for an area might be 45db attenuation or reduction of audible conversations within the area. To achieve this level of attenuation, the requirement forces some construction- specific details to be incorporated. For example, the door or doors into the area will have specialized weather stripping sweeps that minimize sound transmission. The doors must be solid core to minimize sound transmission and add to the physical security.
The walls that enclose the area will often incorporate double 5/8-inch sheetrock that is overlapped so that the seams do not line up on the second layer. Often, 9-gauge expanded metal is welded to the studs prior to applying the sheetrock.
Sound emission or Sound Transmission Criteria (STC) control often includes some electronics that are used for sound masking.
Manufacturers make a sound transducer device - basically an electromagnet for a speaker that is mounted to the walls, doors, ductwork, etc. An amplifier is used to drive the sound masking devices. A CD player is added to allow music to be played, which is transmitted to the walls, doors or other surfaces via the electromagnetic devices. In addition to music, random noise also called pink noise is played over the system to help mask conversations.
Limited access is controlled both physically and electronically. To enable a person access to a high-security area, that person must have access to the front gate, the building entrance, and finally, to the area itself.
There are several checkpoints or layers of access. At the entrance to the classified area, typically there will be a spin dial lock that requires a combination. This lock is a high-security lock that is opened when the area is to be occupied and locked when it is not. There is also an electronic security system to gain entry. This electronic security alarm system can be set up to require one or two people entering security codes to access the area - referred to as a one- or two-man rule.
If the government agency allows, a badge reader can be added to the door locking hardware that will allow access after the spin dial lock has been opened. This means that occupants only have to unlock the combination lock once at the start of the day. Normal operation should occur in a specific order: The combination lock is opened; and then the electronic security alarm system is accessed, which activates the electronic access control badge reader. At the close of working hours, the electronic security alarm system is secured, which deactivates the electronic access control badge reader, and the combination lock is secured again.
This approach assumes that the database for the area electronic access control badge reader system resides in the classified area and has proper approval levels to ensure only authorized personnel have access. The computer that this badge reader database resides on can be considered classified to the same level of the area itself. It enables flexibility and ease of access while providing a high level of security.
Documentation of Personnel Movement
An area that is not entered often or has few personnel gaining access can be largely controlled by "sign in" logs that are in the area - one for employees and one for visitors.
In most high-traffic applications, however, documentation of the various personnel entering the area is accomplished electronically. The electronic access control badge reader can add a level of documentation, indicating who was in and out at a certain time.
Each person with approval to access the area will have his or her own code number for the security alarm keypad. If a badge read is also required to access and secure the alarm system, there is additional assurance that the person controlling the system is who they say they are. This approach is referred to as two-credential verification.
Detection of Unauthorized Access
For the most part, unauthorized access is handled via the electronic security alarm and electronic access control system. The access control system controls entry after the area has been accessed, but when the area is secured, the electronic security alarm system will detect unauthorized entry.
The alarm system should include door sensors, motion detectors and specialty sensors. Any doors into or out of the secure area should have door sensors which will be deactivated when the electronic security alarm system has been accessed. If there is a second door at the end of the vestibule, the second door sensor will remain active, but will be shunted once there is a valid badge read.
Upon accessing the electronic access control system, motion detectors should also be bypassed. All other doors will normally remain active.
Specialty alarms such as proximity safe alarms or vibration alarms may or may not be active when the main security alarm system in the area is accessed. These devices can be accessed separately to add additional security. If the electronic security data gathering panel is not in the secure area, a vibration detector can be added to the data gathering panel and remain active to comply with UL2050.
There are several options that allow use of the secured doors for other than emergency evacuation. First, an area occupant must call the Security Control Center (SCC) to notify them that a secured door will be opened. Second is to have a shunt button by the door to temporarily bypass the door. Lastly, a badge reader with a timer could be used to record the person who bypassed the door and keep the alarm shunted for a predetermined time.
To reduce the number of nuisance alarms at the SCC and to allow authorized personnel to effectively use the secure area to perform their day-to-day jobs, there must be a thorough plan. The plan must include the security equipment, the procedures for using the equipment and the overall security/operational procedures.
The design of high-security areas is a challenge to ensure the desired level of security and provide flexibility and ease of operation, in that order.
Bob Pearson is president of The Protectorate Corporation and a Registered Professional Engineer and a Licensed Security Consultant. He published a book "Electronic Security Systems" and has published numerous articles. He is a member of National Standing Architecture/Engineering Counsel of ASIS International and has presented numerous seminars at the national and international conferences and workshops. He has over 30 years experience in electrical engineering and electronic security systems design, installation, testing and maintenance.