Radio Monitoring in the Security System of Commercial Facilities. Part 1

#radio monitoring

ROSSI Corporation

Manual for security officers, heads of business and commercial structures

INTRODUCTION

An integral part of the market mechanism is the concept of commerce.

Any modern enterprise in a market economy is forced to operate in a competitive environment.

At the same time, however, unfair competition is possible, consisting of the violation of the obvious rights of the owner to industrial or intellectual property and manifested in the unauthorized acquisition of secrets of reproduction of someone else's products, trade and financial secrets, interference in the business activities of the organization or the personal lives of its employees.

With the revival of the market and the emergence of competition in Russia, a previously absent phenomenon has emerged, such as industrial espionage, which, first of all, is unauthorized access to commercially important information using intelligence technical systems for covert information collection, secretly installed in the premises of commercial facilities of interest, where confidential information circulates.

The range of these devices is quite extensive today and includes various radio microphones (radio bugs), telephone radio repeaters, radio stethoscopes and other special equipment, most often transmitting intercepted information over the air and combining high technical parameters with good camouflage quality and ease of installation at the facility.

With their help, it is possible to transmit information over a distance of up to several hundred meters, and the duration of operation ranges from several hours to a year or more.

Certain types of listening devices do not require special installation at all and can simply be thrown into the premises of interest for a short period at any convenient time.

In these conditions, the commonly practiced periodic checks of office premises, cars and residential apartments for radio bugs are becoming less and less effective, since the threat of planting such devices is practically constant.

Serious problems also include organizing control over the loyalty of employees conducting negotiations using cellular radio telephones or radio stations, as well as identifying side emissions from technical means of processing, storing and transmitting information used at the facility.

Taking into account the above, the modern concept of protecting confidential information circulating in the premises or technical systems of a commercial facility requires not periodic, but practically constant monitoring of all radio emissions in the area where the facility is located.

In this regard, a new term has recently appeared in the lexicon of security services of commercial structures in Russia and other CIS countries — «RADIOMONITORING«, which involves the study and monitoring of the radio environment in the area of ​​a commercial facility, the search for and detection of legal (registered) and illegal (unregistered) radio transmitters and sources of other radio emissions.

An important advantage of radio monitoring (RM) is the continuity of receipt, reliability and relevance of the data obtained.

Continuity is achieved by the constant operation of monitoring tools, reliability — by the documentary nature of the incoming information, relevance — by the timeliness of receiving the data necessary for decision-making.

Multichannel scanning receivers are currently used as the main means of radio monitoring, allowing for automatic searches for radio signals on the air and continuous monitoring of preset communication frequencies.

In addition to scanners, other necessary equipment is also used in the process of conducting RM — portable frequency meters, radio spectrum analyzers, broadband antennas, bandpass and rejection filters, low-noise antenna amplifiers, speech noise reduction devices, high-frequency cables with low losses, etc.

As in other similar areas of activity, the efficiency and effectiveness of radio monitoring depend not only on the availability of expensive equipment, correct installation of antennas and cables, but also on the techniques, methods of work, and the qualifications and experience of radio operators.

Monitoring radio broadcasts is not only an exciting activity with scanning radio receivers, but also constant, sometimes round-the-clock work of qualified specialists, ensuring the operation of electronic equipment for monitoring radio ranges, identifying and measuring radio signal parameters, recording, storing and processing information obtained by radio monitoring, etc.

Sometimes large financial resources are spent on ensuring this activity, but with the correct organization of this work, they are more than compensated for by the results obtained.

This manual, designed primarily for employees of security services of commercial facilities, is an attempt to consider in practical terms ways of solving the main problems that most often arise in the process of radio monitoring.

The main attention in the manual is paid to issues of organizing work on RM, processing the results obtained in the process, examining the parameters and characteristic features of various sources of radio emissions, the optimal selection of equipment necessary for effective radio monitoring, etc.

1. MAIN OBJECTIVES AND CONDITIONS OF RADIO MONITORING

In the process of regular radio monitoring, it is possible to solve the following main tasks to ensure the security of a commercial facility:

• detection of emissions from radio means of unauthorized information retrieval introduced into the premises of the facility, and their localization;
• monitoring compliance with communication discipline when employees use open radio communication channels;
• detection of informative side emissions arising from the operation of office equipment, computers, etc.;
• assessment of the effectiveness of technical means of information protection used at the facility;
• monitoring the location and condition of the company's vehicles in real time using satellite navigation systems;
• accumulation of data on the radio-electronic situation in the area of ​​the facility's location and detection of new signals.

When solving any of the above tasks in the process of radio monitoring, it is necessary to take into account a number of basic conditions, without which it is impossible to ensure the effectiveness of the event.

First of all, these mandatory conditions include:

1. The planned and regular nature of radio monitoring in the facility area.

2. The mandatory presence of operators specially trained for this work, since the accuracy and completeness of data obtained using radio monitoring largely depend on their professional training, ability to correctly assess the situation, and ability to perceive and identify the necessary information.

3. Knowledge by operators of the structures of radio communication systems and methods of transmitting information through their channels, as well as the characteristic features and main operating ranges of radio equipment for covert information collection.

4. Mandatory compilation and regular updating of special maps and tables of radio air occupancy in the facility area. Knowledge of frequency ranges, operating modes and parameters of signals of «legal» means of communication, radio broadcasting and television monitored in the facility area.

5. Careful analysis of all data obtained during radio monitoring, comparison with the facility operating mode and previously accumulated information on the radio situation in the facility's surroundings.

6. Equipment at the facility of a special room for radio monitoring, optimal selection and placement of technical equipment.

2. METHODS AND MEANS OF TRANSMITTING INFORMATION VIA RADIO COMMUNICATION CHANNELS

In order to effectively solve the problems solved in the process of radio monitoring, it is necessary to have a sufficiently good understanding of the organization of existing radio communication systems, standards and methods of transmitting information through their channels, especially in the UHF and VHF ranges, which are of most interest to security services, since it is in these ranges that most radio systems for covert information collection operate, as well as operational radio communication systems for departmental and general use.

In accordance with international agreements, the use of all radio frequencies is strictly regulated. The Radio Regulations cover the entire frequency range from 3 kilohertz (kHz) to 3000 gigahertz (GHz), which is divided into sub-ranges in accordance with Table 1.

Table 1.

The distribution of frequencies between different services varies for the regions into which the globe is divided. There are three such regions. Region No. 1 includes the entire territory of the former USSR.

One of the most common methods of transmitting large amounts of information over significant distances is multi-channel radio communication using radio relay lines and space communication systems.

Radio relay communication is communication using intermediate repeater amplifiers. Multichannel radio relay lines (RRL) are usually laid near highways to facilitate servicing of remote repeaters, which are located at dominant heights, masts, etc. The RRL operating range is from 100 megahertz (MHz) to tens of gigahertz (GHz). In space communication systems, hundreds of messages are also transmitted simultaneously via a repeater satellite, which is in a circular geostationary orbit in the equatorial plane.

The global strategy for the modern development of radio communications is the creation of international and global public radio networks based on the widespread use ofmobile (mobile) radio communications,

Currently, the dominant position in the mobile radio communications market is occupied by:

• departmental (local, autonomous) systems with communication channels rigidly assigned to subscribers;
• trunking radio communication systems with free access of subscribers to the common frequency resource (Trunking);
• Cellular Radio Systems;
• Paging Systems;
• Cordless Telephony.

Communication systems with fixed channels have been used by government and commercial organizations, law enforcement agencies, emergency services, etc. for a long time. They can use both simplex and duplex communication channels, analog and digital methods of masking messages, and have high communication efficiency.

Depending on the type of radio stations used, several types of networks of this type are possible:

• radio networks without individual calls, operating on one frequency according to the principle of «one speaks —everyone hears»;
• radio networks with individual (selective) and group calls, in which it is possible for several groups of users to operate on one frequency without mutual interference, calling one specific subscriber, a group of subscribers, or a general call.

However, such systems also have a number of disadvantages that limit their capabilities. Thus, the maximum number of subscribers served on one frequency strongly depends on the intensity of communication, duration of the communication session, etc. In most cases, their capacity does not exceed 10-15 subscribers, and the range is limited to 5-10 km for portable and 15-20 km for car radio stations, in addition, it significantly depends on the nature of the terrain and in urban conditions can be 2-3 times less. In these systems, due to departmental disunity, the frequency resource is ineffectively used, there is no unification of equipment, and there is a violation of electromagnetic compatibility.

The range of fixed channel systems can be expanded several times by using stationary control stations or repeaters with powerful radio transmitters and high-elevated antennas. If it is necessary to cover large areas with radio communications, a repeater network can be installed.

The main frequency ranges for fixed channel networks are: 100-200, 340-375, 400-520 MHz.

The most optimal at present is the use of public mobile radio networks (trunking, cellular), since they provide subscribers with a greater variety of services — from the formation of dispatch communications of individual services to automatic access to subscribers of city and long-distance telephone networks, and also allow a sharp increase in network capacity.

In these networks, any subscriber has the right to access any unoccupied network channel and is subject only to the discipline of mass service.

The term «trunking» refers to a method of equal access of network subscribers to a common dedicated bundle of channels, in which a specific channel is assigned for each communication session individually, depending on the distribution of the load in the system.

Communication between individual subscribers in such a network is carried out mainly through a special receiving and transmitting base station. The radius of the base station in urban conditions, depending on the frequency range of the network, the location and power of the base and subscriber stations, ranges from 8 to 50 km. Trunking radio communication networks deployed earlier in the regions of Russia mainly operate in the ranges of 130-174 and 403 — 512 MHz (SmarTrunkll, StartSiten, etc.).

The minimum number of channels at each base station is three, with the system capacity being 30-40 subscribers per channel. The frequency spacing of adjacent channels in these systems is 12.5; 20 or 25 kHz. The operating mode of subscriber radio stations is half-duplex (see Appendix 1), the frequency spacing between reception and transmission in the conversational channel is 4-10 MHz.

Recently, multi-zone (having several base stations) trunking networks in the ranges of 806-825/851-869 and 896-901/935-940 MHz (for example, Multi-Net) with a frequency spacing of 45 MHz and the ability to operate in duplex mode have become widespread. The throughput of such systems is more than 100 subscribers per channel.

General trends related to the integration of mobile radio communication systems of identical purpose, expansion of the service area, development of communication services and interaction with modern digital communication networks have led to the need to develop a pan-European standard for digital trunking systems, called TETKA. This multi-zone system operates in the range of 380-400 MHz and is aimed at those subscribers who need high-quality speech transmission and encryption capabilities. The frequency spacing of adjacent radio channels is 25 kHz, the duplex spacing of radio channels for transmission and reception is 10 MHz.

Trunking communications uses several different approaches to finding a free communication channel. In one case, the function of finding a free channel and the procedure for entering into communication is assigned to the subscriber station, which carries out a scanning search for an unoccupied channel in the entire allocated frequency range. In another case, the analysis of the occupancy of communication channels is assigned to the control subsystem of the base station, while the assignment of a free (calling) communication channel to the subscriber station is carried out on a specially allocated «organizational» channel. Moreover, in such systems there is the possibility of promptly switching the organizational channel to another frequency when interference occurs.

The main consumers of trunking communication services are law enforcement agencies, emergency services, the army, private security services, customs, municipal authorities, repair and utility services, trade, warehouse and distribution centers, security and escort services, banks and collection services, airports, energy substations, construction companies, hospitals, forestry, transport companies, railways, industrial enterprises.

Cellular radiotelephone communications occupy a special place among public communication networks. The cellular principle of network topology with frequency reuse has largely solved the problem of frequency resource shortage and is currently the main one in the public mobile communication systems being created.

The structure of cellular networks is a set of small service areas adjacent to each other and having different communication frequencies, which can cover vast territories.

Since the radius of one such zone (cell) does not exceed, as a rule, several kilometers, in cells that are not directly adjacent to each other, it is possible to reuse the same frequencies without mutual interference.

Each cell contains a stationary (base) radio transceiver, which is connected by wire to the central station of the network. The number of frequency channels in the network usually does not exceed 7-10, and one of them is organizational. The transition of subscribers from one zone to another is not associated with any restructuring of the equipment. When a subscriber crosses the zone boundary, he is automatically provided with another free frequency belonging to the new cell.

Currently, three standards of cellular radiotelephone communication are used in Russia: analog NMT-450, analog-digital AMPS/D-AMPS and digital GSM. The NMT-450 and GSM standards are accepted as federal, and AMPS/D-AMPS is oriented towards regional use. The most important parameters of these standards for radio monitoring are given in Table 2.

Table 2.

Personal radio paging (paging) provides wireless one-way transmission of alphanumeric or audio information of a limited volume within the service area.

According to their purpose, personal radio call systems (PRCS) can be divided into departmental (local) and general use.

Departmental PRCS provide for the transmission of messages in local zones or in a limited area in the interests of individual user groups. As a rule, the transmission of messages in such systems is carried out from dispatch control panels without interaction with the telephone network.

Public personal calling systems are understood to be a set of technical means through which messages are transmitted via a radio channel using the city telephone network.

There are two ways to organize a paging network: cellular and radial. With the cellular method, the network is a number of low-power transmitters with coverage areas closely adjacent to each other. A small radius of coverage areas allows you to build zones of any shape: along highways, repeating the outlines of the outskirts of the city, etc. With the radial method, high-power transmitters are installed, allowing reception in a radius of 100-150 km.

The operating range of the SPRV is 80-930 MHz. Users of paging systems are, first of all, businessmen, merchants, various emergency call services, government agencies, commercial banks and firms, and various cargo transportation services.

Wireless telephone systems (WTS) at the initial stage of their development were intended mainly to replace the telephone handset cord with a wireless radio line in order to provide greater subscriber mobility. Further development of this type of communication, especially the transition to digital methods of information processing, significantly expanded the scope of application of WTS.

In analog-type wireless telephone systems, most often used in residential premises and small institutions, individual-use BPTs are used, consisting of a base station (BS) connected to the city telephone network and a portable radiotelephone (PT). When BPTs are used in large companies as an intra-institutional means of communication, branched networks of low-power radiotelephones are organized, the operating principle of which is similar to cellular networks. These systems mainly use digital signal processing methods, providing more secure encryption of transmitted messages.

Both analog and digital cordless telephones operate in duplex mode on several channels, with the channel being selected automatically from among the unoccupied ones. The range of the BPT, depending on the type of equipment and operating conditions, is 25-200 m. The power of the radio transmitters does not exceed 10 MW.

Currently, analog BPTs operate in the following main frequency ranges:

• 46, 610-46, 930 MHz (BS)/49, 670-49, 990 MHz (RT). In the network — 10 channels;
• 959, 0125-959, 9875 MHz /914, 0125-914, 9875 MHz (40 channels);
• 885, 0125-886, 9875 MHz /930, 0125- 931, 9875 MHz (80 channels);
• 1, 642-1, 782 MHz/47, 456-47, 544 MHz (8 channels);
• 26.3125-26.4875 MHz/41.3125-41, 4875 MHz (10 channels).

The following main frequency ranges are allocated for digital BPT: 804-868 MHz («Telepoint» — 40 channels); 864-868 MHz (40 channels); 866-962 MHz (32 channels); 1880-1990 MHz («DECT» — 120 channels).

To protect communications and improve noise immunity in analog BPT networks, the following technical methods are used: automatic change of the transmission channel frequency, change of the transmitter output power depending on the distance between the BS and the RT, speech spectrum inversion.

Automatic vehicle location (AVL) systems using global space radio navigation systems (GPS) are mainly used by emergency services, law enforcement agencies, commercial and government organizations when transporting valuable and dangerous goods.

The principle underlying GPS/AVL is as follows: each vehicle is equipped with a miniature multi-channel receiver of navigation signals continuously emitted by several low-flying satellites.

After appropriate signal processing, the on-board processor determines the coordinates of the location, speed and direction of movement of the vehicle. To transmit this information to the control center, either a trunking communication channel, or a cellular network, or a global satellite communication system is used.

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