Network technologies in perimeter security systems.
Fig. 1. Example of the Multiplex 2000 network system configuration
Introduction
Modern technologies offer a wide range of equipment and technical solutions for problems related to perimeter security. Apparently, it is not easy to find a physical principle that would not be used in the creation of systems for protecting the boundaries of objects. Domestic and foreign enterprises produce security systems of various types for this purpose: optical beam, passive infrared, radio beam, radio wave, with vibration sensors, magnetometric and many others. The equipment produced today allows you to reliably protect almost any perimeter, and the efficiency of the security system depends only on the correctness of the choice and quality of installation.
However, the problem of building a reliable and efficient perimeter security system depends not only on the choice of security devices. The peculiarity of perimeter security systems is that the protected objects can be quite extensive. And this circumstance requires a careful approach not only to the choice of security equipment, but also to the construction of the system architecture, which should ensure control and management of security equipment distributed over a large territory.
If the perimeter of your facility is relatively small — from several hundred meters to, say, one and a half to two kilometers (up to 15-20 separate security zones), then the problem of building a system can be solved in a classical way. This means that sensors from all security zones are connected to the central equipment using multi-pair cables that transmit alarm signals, sensor opening signals, failure signals, etc. to the security post. However, such a solution is not always effective for extended facilities. Let's imagine that the length of the protected perimeter is 10-15 km, which is quite typical, say, for a large industrial facility or an airport. For such a facility, the number of security zones already amounts to many dozens. And the classical solution for building a system can no longer satisfy the user due to the organic shortcomings inherent in this system.
Modern network communication technologies allow a new approach to solving the problem of building a security system for extended perimeters. Below we will try to analyze this problem and show how leading foreign development companies working in this segment of security technologies solve it.
What are the problems, actually?
Let's assume that the protected perimeter is divided into zones 100 m long and the maximum distance from the most remote zone to the security post is 7 or 8 km. If the security device has standard relay outputs (for alarm, tamper, failure signals), then from each zone it is necessary to lay cables with copper twisted pairs transmitting relay signals. The task of transmitting relay signals over such distances is in itself associated with the risk of electromagnetic interference induced on the signal cables and may require the use of additional equipment (relay repeaters, additional power supplies, etc.). In addition, with a line length of several kilometers, the cost of the signal cable and additional equipment may already become comparable to the cost of the main security equipment in the remote zone.
Laying multiple signal cables is a rather labor-intensive task, which may require additional infrastructure costs for the facility — laying cable channels, installing additional wells, etc. Obviously, this significantly increases the overall cost of the equipment and the volume of installation work during installation.
A modern security system for an extended perimeter cannot be imagined simply as a set of individual sensors. As a rule, security sensors on the perimeter are supplemented by a video surveillance system, which allows identifying a real intrusion and helps security personnel make the right decisions. Practice shows that for an effective organization of a perimeter video surveillance system, it is necessary to install video cameras at least every 50-70 m. This means that with the classic approach to building a system along the perimeter, it is necessary to additionally lay dozens (if not hundreds) of coaxial cables to transmit video signals to the security post. Here again, it is necessary to solve the problem of compensating for the attenuation of video signals using special repeaters. If we keep in mind that the perimeter security system often requires integrating elements of the access control system, electronic gate locks and local lighting floodlights, it is obvious that the communication infrastructure of an extended perimeter security system can be a very complex and expensive problem to implement.
Fig. 2. Configuration of the Jitter-net system
Another problem for extended perimeters may be routine engineering work with security equipment. Modern security sensors, as a rule, have a developed system of computer diagnostics, adjustment and control of operating parameters, viewing of the archive of alarm signals, etc. However, with the classic scheme of building a security system, when only relay alarm signals are sent to the security post, all the «intelligent» functions of the sensors cannot be really used.
The above circumstances stimulated the use of communication technologies, which allowed a new approach to the problems of constructing systems for protecting extended perimeters.
The use of network technologies allows integrating various security devices on the basis of a single system with the ability to monitor, remotely control and configure them. At the same time, it is possible to dramatically reduce the number and length of signal cable lines, make the system expandable with a minimum of costs for additional communications and control equipment.
Below we will briefly analyze specific «network» solutions from some of the world's leading manufacturers focused on building security systems for extended perimeters.
Fig. 3. Jitter-net network switch unit
Various approaches and solutions
The Italian company GPS Standard is well known for its perimeter security systems. These include the vibration-sensitive system CPS and its microprocessor modification CPS Plus, using a coaxial microphone cable; the barometric GPS system for underground installation; multi-beam infrared barriers of the IPS series; tension strain gauge systems WPS, etc.To combine security equipment into a single complex, GPS Standard has developed the Multiplex 2000 system. The system is a communications network for data transmission at a speed of 115 kBaud using a specially developed protocol called COM115. The network operates under the control of the UCP 2000 (Universal Communication Processor) control unit, housed in a 19” rack-mountable case.
Up to 64 security devices of 16 different types from the range manufactured by GPS Standard can be connected to the UCP 2000 control unit via one 4-wire cable (Fig. 1). The network configuration when connecting to the control unit can have two options: the first — with the connection of two independent beams to two ports of the control unit, the second — with the connection of a communication cable in the form of a ring. In the first case, the length of the protected perimeter will be up to 10 km (5 km for each beam), in the second — only 5 km. However, in the second case, a very important advantage appears: if the network cable breaks, all connected devices will remain in touch, which significantly increases the security of the system.
If it is necessary to connect more than 64 devices, additional UCP control units are used, which are connected to the personal computer via the same COM 115 bus or via the RS 485 interface. The number of additional control units connected in this way can reach 64.
The new generation of GPS Standard security sensors feature built-in microprocessors, digital signal processing, violation pattern recognition and a self-learning mode. These security devices, which have received the additional Plus index, have the ability to directly connect to the Multiplex 2000 communication system via the COM 115 bus.
Fig. 4. Structural diagram of the DuoTek Net system
To connect previous versions of security devices to the Multiplex 2000 system, as well as other analog sensors with relay outputs, the system has a special interface module (Sensor Interface Unit).
When connecting a personal computer to the UCP 2000 control unit, it becomes possible to monitor the system, remotely configure and test security devices connected to the network using special software. The control system allows recording and analyzing analog sensor signals in real time without losing connection with other sensors, storing and editing the event log. A typical Multiplex 2000 configuration diagram is shown in Fig. 1.
The software developed for system control is designed to work in the Windows operating system environment and has a traditional Windows application interface with drop-down menu windows.
Alarms, accidents, openings, etc. from the control unit are sent to relay modules for transmission to other control panels or other security systems (notifications, video surveillance). At the same time, each relay output can be remotely configured using software in accordance with the requirements.
The use of a special data transfer protocol allows you to protect the system from unauthorized intrusion and data interception, which is especially important for facilities with increased security system requirements. However, the disadvantages of the system include the need to use devices that support this protocol, which is not very convenient when expanding the system. This also increases the cost of the complex compared to systems using security devices with standard network protocols.
Among the developments of the Canadian company Senstar-Stellar, there are several network systems for managing security equipment at the facility, but we will focus on only two of them.
The MagNet system is developed on the basis of a communication line using standard TCP/IP network protocols. The MagNet system allows you to combine into a single security complex not only perimeter security devices from Senstar Stellar (Innofence, Yale, Barricade), but also security sensors from other manufacturers, as well as video surveillance systems, access control, voice notification, fire alarm, etc.
Fig. 5. Rack of the central equipment of the IB-System
A personal computer running the Windows NT operating system is used as a server to control the system. Special UWS (User Workstation Software) software installed on the system operator terminals is used to monitor and configure the system. A plan or photograph of the facility can be exported to the UWS graphical interface to facilitate the visual perception of the structure of security zones and signals received from perimeter sensors. Interactive pictograms of security equipment can also be applied to the facility plan, which will be highlighted in different colors when the sensor status changes. Access to the system is protected by personal passwords and has a hierarchical structure.
Video servers with DTS-1000 video capture cards manufactured by Magal and special software are used to integrate the video surveillance system into the MagNet system. One server can receive and transmit signals from 32 video cameras.
The Senstar 100/Sennet system from Senstar-Stellar is designed for facilities with increased requirements for the level of security, as well as the reliability of perimeter systems and control and information collection systems, such as airports, communication centers, military bases, oil and gas plants, power plants, etc.
Like the previous ones, this system is designed to combine perimeter security systems, video surveillance systems and additional security and auxiliary devices that can be installed at the facility into a single security complex.
The Senstar 100/Sennet system uses both fiber-optic and copper cable (twisted pair or coaxial) as a data transmission medium, with redundancy provided for each communication line. Data is transmitted in the network using a special Sennet protocol. The protocol has a powerful error processing algorithm, which allows receiving correct data even in the presence of interference in the line and unstable network operation.
The server that controls the system runs under the QNX operating system. This operating system is used to solve mission-critical tasks, i.e. tasks with very high requirements for response time to emergency situations, requirements for reliability and continuity of control. The system has two server stations to increase reliability. To reduce the operator's response time to incoming alarm signals, the Senstar 100/Sennet system uses tactile panels (Touch Panel) instead of conventional monitors.
Fig. 6. Example of the IB-System communication network configuration
The English company Geoquip, known for its developments in the field of vibration-sensitive systems with microphone sensor cables (Guardwire, Defender, MikrAlert), began production of a new network system called Gthernet in 2006. The Gthernet system allows for the unification under common control of not only the equipment of Geoquip's perimeter security systems, but also security equipment from other manufacturers, as well as a number of additional systems that can be installed on the perimeter, such as a video surveillance system, an alert system, an access control system, a weather station, etc.The Jitternet system is a communication network designed to transmit alarm signals from security devices to the operator's console via fiber-optic or copper cable, as well as for monitoring and remote configuration of equipment, viewing and editing the event log. The network operates in duplex mode at speeds up to 100 Mbit/s. An example of a Jitternet network configuration is shown in Fig. 2.
The network is controlled by a base station, i.e. a server based on an industrial computer running the Linux operating system. This server is an unattended device; its parameters are configured by the manufacturer and it does not require additional configuration. However, if necessary, the user has the option of connecting a keyboard and monitor for testing or additional debugging of the network.
The optical cable of the communication network is connected to the base station via optical fiber-twisted pair converter units, which are structurally located inside the base station housing.
The communication network is built using the ring topology. This configuration increases the security of the system in cases of accidental breakage or intentional damage to the optical cable, since all devices included in the network will be able to remain in touch after the cable breaks, transmitting signals via two independent beams. The length of the optical ring is not limited, but special devices — switches (nodes) must be installed every 1.5 km of the optical line, which, in addition to the repeater function, are used to connect security devices and to create branches from the main ring. When using copper cable (twisted pair, category 5 cable) to connect devices to switches, its length should not exceed 100 m.
The Jitternet switch (Fig. 3) is a maintenance-free device with three ports with an RJ45 connector. Thus, up to three Ethernet-compatible devices can be directly connected to each switch. The switch unit is placed in a dust- and moisture-proof aluminum case for installation directly on the perimeter. The Jitternet switch is an analogue of the switch/hub device used in a standard Ethernet network.
The Jitternet system uses standard TCP/IP protocols to transmit signals, which ensures easy installation and integration of monitoring and control systems, including video surveillance equipment, perimeter security systems of the «Mikralert» series, as well as security alarm and access control equipment from other manufacturers.
The Jitternet system has three types of different additional modules that adapt signals from external devices when they are connected to the network via switches. These additional modules include the following devices:
1. Interface module (LIM – Legacy Interface Module) for connecting security sensors with relay outputs to the switch. This module is installed directly on the switch board. The module provides connection to the switch of up to 8 security sensor loops and up to 8 relay outputs.
2. Serial and audio signal transmission module (SAM module). It is connected to security devices via the RS 232 interface (video surveillance systems, weather stations, etc.) or is used to connect MicroAlert series analyzers to switches. The module also has an input for an analog audio signal, which is digitized and transmitted to the network. The base station decodes this signal into analog form and plays it back through the connected audio system in the event of an alarm.
3. Expansion module (GEM – Gthernet Expander Module). It is similar in purpose to the LIM module, but allows you to connect a larger number of external devices — up to 96 security sensor loops and up to 512 relay outputs. These functions are implemented using the CenterAlert system units from Ge-okuip.
To manage and monitor the Jitternet system, Geoquip has developed special software called Geolog. The Geolog program uses the Linux platform, has an open architecture, and connects to the Jitternet network directly via the Ethernet network interface. The program is installed on a personal computer, which will be used as the operator's workstation. There can be any number of computers connected to the network as operator consoles. The system login has a hierarchical structure and is password-protected.
Fig. 7. Graphic interface of the IB-Test-Map control program
The use of standard TCP/IP network protocols allows a wide range of equipment (IP video cameras, video storage devices, etc.) that support these protocols to be directly connected to the Jitternet network, as well as the system to be freely scaled, including any amount of necessary equipment and creating a network of any topology within the Ethernet standard in the branches of the optical ring.
Using a fiber-optic cable as the main information backbone allows for an effective solution to the issue of the maximum length of the protected perimeter, which is especially important for large facilities. Using one fiber-optic cable to transmit all signals allows for significant savings on copper signal cables that would need to be laid from each system to the security post with a classic system design.
The English company Detection Technologies Limited (DTL) recently released the DuoTek Net network system, designed for perimeter protection. The structural diagram of the system is shown in Fig. 4.
The system uses electromagnetic microphone sensor cables as a sensitive element, which are attached directly to the fence. The signals from the sensor cables are processed by analyzers included in the RS485 standard communication network. Data exchange in the network is monitored by a base station located at the security post. The computer of the security complex control system is connected to the output of the base station via an IP port.
The system can include up to 32 two-zone analyzers, which allows servicing up to 64 security zones with sensor cables. In addition, up to 128 additional discrete security sensors can be connected to the system.
Each analyzer is equipped with RS485 signal repeaters; when using a standard twisted pair cable, the maximum distance between adjacent analyzers is 600 m.
Using a special setup program, the system provides remote monitoring and adjustment of all operating parameters of the analyzers. Each analyzer is equipped with a built-in memory module that stores up to 1000 alarm events.
Fig. 8. Rack of the central equipment of the IB-System
The DuoTek Net system is distinguished by its simple architecture and a minimum of electronic modules on the perimeter, although this is compensated by minimal capabilities for connecting additional equipment. Each system analyzer has 4 inputs for additional sensors, as well as 4 output relays for controlling peripheral equipment on the perimeter (locks, floodlights, etc.).
The system allows transmitting and listening to audio signals from sensor cables connected to analyzers over the network, and it is possible to listen to both real-time audio and audio signals stored in the analyzer memory modules. The Italian company CIAS Elettronica srl specializes in the development and production of radio beam security sensors for perimeter protection. Among the latest developments of CIAS are radio beam barriers with built-in microprocessors, network interfaces, digital signal processing, as well as an intruder pattern recognition system based on the use of fuzzy logic algorithms.
One of the latest developments of CIAS is the IB-System network communication system. The system allows you to control the entire complex of CIAS security devices, as well as additional equipment from other manufacturers.
The central equipment of the IB-System system includes the IB-Server server unit, the IB-Hub concentrator unit and the IB-Island relay-indicator units. The units are placed in a standard 19-inch rack with a height of 3U (Fig. 5).
The RS485 protocol communication network is capable of connecting up to 128 single-position security devices or up to 64 two-position microwave barriers manufactured by CIAS. Optical fiber or copper cables (twisted pair) are used as the communication medium. An example of the IB-System network configuration is shown in Fig. 6. Two-position radio beam sensors of the ERMO 482x PRO series, single-position microwave sensors Armidor, and combined beam (microwave + IR) sensors Pythagoras are connected to the central rack using an optical fiber cable.
The peripheral equipment components of the IB-System include field amplifiers-splitters of network signals of the RS485 standard (see Fig. 6). The FMC-Rep series amplifier-splitter is equipped with 5 RS485 ports, which allows you to connect up to several dozen security sensors with network interfaces to it.
To connect security devices with relay outputs, specially developed interface modules of the IB-Transponder series are used, assigning an individual address to each device connected to it, allowing this device to be recognized in the network. The network has a ring configuration, which increases its reliability, since in the event of a fiber optic cable break, it allows two separate beams of the network to remain operational.
Using a personal computer with IB-Test software connected to the IB-Server module via the RS-232 port, you can receive signals from connected security devices in real time, view event logs, and remotely configure digital sensors from CIAS. The system allows you to transmit analog signals from radio beam sensors to the operator's monitor for analysis, signal level parameters on the receiving and transmitting units of radio beam sensors, threshold values of monitored parameters, supply voltage, and other data necessary for diagnostics and selection of optimal device settings.
Fig. 9. Example of the IB-System communication network configuration
The software has a clear graphical interface for displaying and configuring the operating parameters of security devices, a built-in event log, in which, in addition to recording the event, device address and date, you can view an archive of analog signal records from this device (the function is only available for microprocessor sensors).
The use of the IB-System is economically justified at long-distance facilities, since its application minimizes the costs of signal cable lines, allowing them to be replaced with a common fiber-optic or copper cable. To display alarm signals, a personal computer with software is used, the graphical interface of which allows you to display a plan of the facility and quickly localize the alarm location, reducing the response time of personnel. An example of the IB-Test-Map graphical interface is shown in Fig. 7.
So what is the result?
As a result of the brief analysis, we can draw some conclusions:
1. It is obvious that the use of network technologies allows you to significantly reduce the cost and physical volume of cable lines used in the construction of perimeter security systems.
2. The use of network systems is justified on perimeters of considerable length: the perimeter length is several kilometers, the number of security zones is several dozen.
3. The network structure allows for easy changes to the architecture of the security system with a minimum of additional cabling work.
4. The use of network technologies allows for the implementation of the capabilities of «intelligent» security devices on the perimeter — remote monitoring and adjustment of sensors, diagnostics of operating parameters of sensors, access to local event archives, etc. As a result, it is possible to reduce the costs of adjustment, maintenance and repair of equipment.
5. In recent years, there has been a noticeable trend in security systems to use standard communication protocols – RS485, TCP/IP, etc.
6. Network technologies allow for the effective integration of various security systems – perimeter security sensors, video surveillance equipment, access control systems, etc.