). The “pioneers of Russian lands” (SmarTrunk), and yesterday’s leaders (MPT 1327), and LTR, and other protocols found their place here. Finally, today domestic consumers are looking at digital trunking, primarily the TETRA standard.
Trunk Zoo
SmarTrunk
Traditionally, almost all Russian suppliers of trunking communication systems offer SmarTrunk and SmarTrunk II equipment manufactured by SmarTrunk Systems. Its main advantages are low cost, a wide range of subscriber devices, ease of converting conventional radio stations into trunking ones and “unpretentiousness” in frequencies (they can operate in the ranges 146-174, 403-470, 300-344 and 800 MHz, there are even cases of using SmarTrunk in the range 33-48 MHz). It is these properties that have become the reason for the widespread use of such systems in Russia (this phenomenon is more accurately characterized by the word “boom”). Industrial enterprises were the first to be tempted to use SmarTrunk, and at that time there was no talk about compatibility, quality and reliability of communication, expansion possibilities: communication is needed now, and cheaper, because there is simply not enough money for “excesses”. The fact that the miser pays twice was remembered only three years after the start of operation of such systems.
MPT 1327 systems
Systems based on the pan-European MRI protocol 1327 are also widely represented in our country. Here, the most “massive” products are the products of the OTE company (after the merger - Marconi Communications), which were exclusively supplied only to Gazprom and were introduced throughout almost the entire technological chain of production and transportation of the product of this natural monopoly. Second place is still firmly held by the family Accessnet production Rohde&Schwarz. Experts value such equipment for its “German quality”.
Quite a long time ago the system “penetrated” Russia Flyed. English company Flyed Microsystems, which gave it its name, was one of the “progenitors” (together with Motorola and Philips) of the MRI 1327 protocol. However, the company never produced transceiver equipment - it develops only base station controllers (BS), which it sells to other manufacturers, allowing them to be used even without references to yourself. Such controllers are used, say, in 1327 MRI systems from Motorola and Maxon.
System Actionet companies Nokia until the mid-90s, it was actually a monopolist on the Russian market. Deployed on its basis first in Russia (1989) the MPT 1327 protocol network of the Surgutneftegaz company. First The certificate of the State Committee for Communications of the Russian Federation for the trunking system of the MRT 1327 protocol was received in February 1996, also by Nokia (although in it Actionet was called a radiotelephone communication system). Finally, in terms of the number of deployed MPT trunking systems, Nokia ranks 1327 first place in the world.
Today, at least 20 Actionet radio networks are in operation in our country (most of which replaced the Altai system, inheriting its radio frequency ranges - both 300 and 400 MHz). Until the recent fire at the Ostankino Tower, these included the commercial Moscow radiotelephone network of the ACBT operator (according to the management of this company, this network will be restored).
A significant share of the market falls on systems Taitnet. They are produced by the company Tait Electronics(New Zealand), which, along with Flyde Microsystems, developed the first MRI systems, and later acquired a license from the latter to produce its trunking controllers.
It is impossible not to mention the basic equipment TrunkSwitch(MPT 1327 protocol), which was created by an English company Stanilight, and then acquired by the Australian company ADI. TrunkSwitch systems work with almost any subscriber equipment, and at least five of them are deployed in Russia (in Moscow, a commercial network built on the basis of TrunkSwitch is operated by Svyaz Trunk). However, since 1999, production of this system has been discontinued.
Another fairly “old” system of the MRI 1327 standard, which is known by the name of the controller used in it, is also popular on our market - Selectacom. It was developed by Ascom, subsequently purchased by Bosch and finally resold to Motorola Corporation. This equipment is currently supplied by Vada Communications, as well as other strategic partners of Motorola.
Unfortunately, MRI 1327 remains protocol without acquiring status standard, therefore each of its implementations has its own characteristics. And of course, companies involved in network deployment try to use equipment from one supplier in order to get rid of incompatibility problems. At the same time, difficulties associated with the organization of intersystem connections still remain. For example, at least 12 large MPT systems have been built in Russia, whose pseudo-interaction (communication at the subscriber level, ensured by assigning several numbers to each radio station) is achievable with some effort, but actually interaction impossible.
SmartNet, EDACS, etc.
A significant share of the market is made up of systems that use control protocols other than MRI. Among those in our country, perhaps only the following are actually used: those included in the SmartNet family manufactured by Motorola (see “Networks”, 1998, No. 6, p. 27), EDACS from Ericsson (see “Networks”, 1998, No. 7 -8, p. 62) and systems based on the LTR protocol, the author of the initial specifications of which was E. F. Johnson, a well-known company in the world of radio equipment (now Transcript International).
Among trunking networks, one cannot fail to mention the multi-zone radio system SmartZone built on equipment Motorola. It is serviced by the Moscow company MTK Trunk.
So far, the only system with digital radio access operating in Russia is EDACS(Enhanced Digital Access Convertional System) companies Ericsson. Its equipment is designed to operate in three frequency ranges (150, 450 and 800 MHz), and for the last two it is certified in Russia. It is possible to operate EDACS in both simplex communication modes (reception and transmission are carried out alternately) and one-way communication. In our country, according to the author, there are five networks based on this system (St. Petersburg, Tolyatti, Yekaterinburg, Orenburg and Krasnoyarsk).
Protocol-based radio communication equipment LTR“historically” companies supply to Russia Kenwood and E.F. Johnson. There are about a dozen such radio systems installed here, and several years ago their popularity (both in the world and in our country) was quite high. And they owe this to E.F. Johnson, the creator of LTR, which not only made this protocol open (unlike EDACS), but also made every effort to elevate it to the rank of an industry standard, at least de facto. The equipment produced operates in the ranges of 400, 800 and 900 MHz.
And of course, one cannot fail to mention the system ESAS companies Uniden, the control protocol of which is an extended modification of LTR. It is characterized by continuity and full compatibility with LTR. The radio equipment is designed to operate in the frequency ranges 806-825 and 851-870 MHz and is capable of providing full-duplex communication (information is transmitted and received simultaneously). The network created on the basis of such devices is operated by Region Trunk.
Of course, this is far from a complete list of trunking systems that have found their application in our country, but, in the author’s opinion, the most common of them have been named.
Frequencies
When choosing subscriber equipment, you need to know which frequency ranges are available to Russian civilian consumers. Military structures and public security services have fairly large “own” sections of the spectrum and usually do not experience “frequency” difficulties when deploying their radio networks.
In our country, frequencies for analogue systems are allocated based on the decision of the State Communications Supervision Authority. To obtain the denominations listed in the decision of the SCRF dated April 27, 1998 (Protocol No. 6/3 “On the use of radio frequency bands 300-308 and 336-344 MHz by radio means of land mobile and fixed services for civil use”), which applies to all legal and physical persons, SCRF is not required to be “disturbed”. We quote this decision to remind readers for what purposes these radio frequency bands are allowed to be used:
“... the bands 300-308 and 336-344 MHz are used to create radial, radial-area systems for land mobile and fixed services for civil use, including using trunking technology for access to radio channels, under the conditions that:
- radio frequency bands 300.0125-300.5125 and 336.0125-336.5125 MHz are used within the coordination zone only for organizing dispatch radio communications with ships and radio communications between ships on the inland waterways of the country;
- radio frequency bands 307.0-307.4625 and 343.0-343.4625 MHz are used for the “Transport” train radio communication system on specific railway lines in accordance with the decision of the State Committee for Radio Frequencies of Russia dated July 5, 1993, protocol No. 13/2;
- radio frequency bands 307.5-308.0 and 343.5-344.0 MHz are used throughout the country by radio means of regional rural radiotelephone communication networks.”
To provide communication services using radio equipment operating on denominations or spectrum sections of any other ranges, in addition to the decision of the State Communications Supervision Authority, a special decision of the SCRF is also required. The main document here is the “Table of distribution of frequency bands between radio services of the Russian Federation in the frequency range from 3 kHz to 400 GHz,” in which “everything good has already been sorted out.” Therefore, when purchasing any equipment, you need to think not seven, but 777 times, whether the frequency range in which it is designed to operate is available.
Closer to the topic
Prices
If the infrastructure equipment of trunking networks is comparable in cost to that used in cellular communications, then the prices for subscriber devices of such systems simply cannot be compared. Like any radio equipment of “non-mass” demand, custom radio stations for trunking communications are by no means cheap, especially by Russian standards. Nevertheless, the set of subscriber devices for trunking communications is quite wide and includes not only portable (wearable) walkie-talkies, but also mobile (portable) stations, data terminals, as well as stationary radio stations, which serve mainly for organizing control centers .
The cheapest (about $300) are portable simplex walkie-talkies with a limited number of functions and without a numeric keypad. They are, as a rule, used by closed groups of subscribers who have only one possibility of communication with the “outside world” - an emergency call to the dispatcher. Most often, this is enough for trunk communication users.
Simplex stations have a numeric keypad for dialing numbers and support at least a dozen functions provided by the trunking system. However, their price is much higher (from about 1 thousand dollars), so they are available only to a few privileged users.
Even more expensive duplex devices(from 1700-2500 for analog and up to 2000-3000 dollars for digital systems), which in appearance are almost indistinguishable from cellular handsets, but are still heavier than the latter - mainly due to the impressive weight of the battery (requirements for it in trunking is much higher). Due to the low power of duplex radios (1-1.2 W), their communication range is much shorter than that of simplex ones. Note that according to Russian regulations, connection to the PSTN is permitted only if duplex communication is provided.
Available in both duplex and simplex mobile devices. Moreover, their execution is quite diverse (sea, automobile, motorcycle, railway, etc.). Sometimes such equipment includes a built-in satellite navigation GPS receiver, which allows you to determine the subscriber’s coordinates and transmit them to the dispatcher. The output power of mobile device transmitters is approximately 3-5 times higher than the power of portable equipment, which means they provide a longer communication range.
Stationary radio stations usually created on the basis of mobile phones, but differ from them in a large number of accessories and the presence of additional terminal devices. The output power of mobile and fixed radio transmitters is usually the same.
A relatively new class of devices for trunking communications are data terminals. In analog systems, these are special radio modems that support a specific radio interface, while in digital systems, ordinary subscriber stations equipped with an asynchronous RS-232 data transfer interface are more often used. The cost of analog equipment is determined by the degree of “specialty” of the radio communication protocol, since such terminals are piece goods. Digital ones cost almost the same as digital trunking “tubes”.
The lineup
Although there are not so many manufacturers of basic equipment for trunking communications, this does not impose any restrictions on the production of subscriber devices. Quite a few companies specialize in the manufacture of only custom radio stations, for a wide variety of communication systems - SmarTrunk, ESAS, LTR, MPT 1327, etc. (Table 2).
In the “oldest” trunking systems, such as SmarTrunk, which are characterized by decentralized control, the subscriber radio station is “obliged” to continuously scan working channels in the process of searching for a call signal or an idle BS line. The criteria for choosing such a terminal are scanning speed (no more than 150 ms), reception/transmission quality and cost of the device.
Company SmarTrunk took care of expanding the market for its cheap systems and released a special logical module for radio stations from other companies (Alinco, Vertex, Kenwood, Marantz, Telemobile, Kyodo), which controls the basic functions of the subscriber station operating in the SmarTrunk system (such as scanning, turning on the transmitter, etc. .). In our country, radio stations with this module belonging to the HX and GX series are very popular (produced with the logo Standard; many of them have Russian industry certificates), as well as to the TK series of production Kenwood. Module programming (using a security code) is performed either by the supplier or by the system owner.
The enormous popularity (despite the high cost) of Motorola radios forced SmarTrunk to create a similar module for these devices. In Russia, for example, in recent years, radio stations GP300, GP400, GP40 and GP50 have been in great demand, and to a large extent because they can be equipped with a module for working in SmarTrunk systems, of which there are many deployed here. This organization of production of subscriber radio equipment allows them to be compatible with each other within the SmarTrunk system.
As for duplex communication, in SmarTrunk it is only possible when using mobile devices such as TM-MDT25 (Telemobile), KG-106 (Kyodo), 9200 (Seiki) and some others. These same radios, equipped with a module that combines the functions of SmarTrunk control and a telephone interface, can be used as stationary devices for rural telephony. Among portable (wearable) radio stations, for example, dual-band terminals manufactured by Alinco operate in duplex mode, but in our country it is not allowed to use the 450 MHz band for reception, and 160 MHz for transmission.
Almost all subscriber devices for the SmarTrunk and SmarTrunkII systems comply with the American military standard MIL STD 810 C/D/E, so it is quite legitimate to use them in communication systems used by the military, intelligence agencies, as well as in cases where increased requirements are placed on communication reliability ( rescue service, offshore oil production enterprises, etc.).
Systems using a controller Flyed, in Russia they are most often equipped with subscriber equipment manufactured Motorola(GP1200, GM1200, GP600, GM600). Less actively used are portable H70 terminals from Nokia and even less often - T2000 and T3000, produced by a New Zealand company Tait Electronics. The latter are much more often purchased together with infrastructure equipment for systems based on the MPT1327 protocol, which this company produces. It should be noted that T2000 radios can be supplied with built-in modems for organizing data transmission using the MAP27 protocol.
Selection of subscriber device manufacturers for MPT systems on the Russian market is quite wide: these include Motorola, Nokia, and at least a dozen others (perhaps the most famous equipment is from Kenwood, Marantz and Maxon).
User equipment Nokia“situated” somewhat apart. The company's products are designed to work not only in Actionet, but also in other trunking networks based on MPT 1327. At the same time, Actionet uses an ANN numbering plan (different from that prescribed by the MPT 1343 specifications) and an expanded (compared to that defined in MPT 1327) verification procedure The electronic serial number of the radio station so far allows Nokia to “protect” this system from the “presence” of other subscriber equipment (however, today ANN is supported by the GP1200, GM1200 and T2000 radio stations). Be that as it may, in the field of duplex radios, Nokia is the undisputed leader. Its top-of-the-line models H70, H75 (portable) and R72 are produced for the 330 and 450 MHz bands.
List of subscriber devices produced Motorola, could take up more than one page. The company produces portable, stationary and mobile radios for almost all existing trunking systems, perhaps excluding those corresponding to the LTR protocol and its versions. These are the already mentioned models of the GP (portable) and GM (mobile) series, as well as MTS 2000 (for the StarSite system) and the Spectra mobile terminal (for the SmartNet family). In Russia, Motorola sells equipment not only through many distributors and partners, but also independently.
The most famous manufacturer of radio stations on the market for LTR systems - Transcript International. All models (both portable NPSPAC series and automotive Viking series) are equipped with microprocessor control and digital frequency synthesizers (operating ranges 821-824 and 822-869 MHz). Mobile devices are supplied in two modifications - mounted on the dashboard of a car and remote (installed, for example, in the trunk) with remote control equipment. Transcript also produces duplex devices (NPSPAC series, numbers from 8605 to 8621, as well as Viking GT 8604 and Viking HT 8600). An additional feature provided by Transcript radios is user changeable transmitter output power (from 1 to 2.5 W).
A whole family of trunking radios for LTR-based systems is also produced by the Marantz concern. In Russia, this equipment with the Standard logo can be purchased for operation in the ranges of 450-480 MHz (for example, HX482, HX4800) and 800 MHz (HX590 - 592, GX5910). Note that the transmitter power of the HX59x models is 2 W, and the GX5910 mobile radio is 15 W.
Functions
A typical analog portable radio only supports group communication functions and therefore does not require a keypad or display. For individual communication you need at least function keys and memory for storing numbers. Additional “conveniences” that can be obtained using an LCD display, keyboard, voice control, etc. are usually typical for models costing $1,000 or more.
In addition to the group and individual communication capabilities inherent in trunking, as well as the functions of system-wide and emergency calls, almost all systems in one way or another organize connection to telephone networks - both institutional and PSTN. However, in our country, connection to the PSTN is allowed only when using duplex subscriber radio stations (and there are not so many of them in analog radio networks). In addition, the declared connection actually turns out to only provide communication with the PBX or the dispatcher. But the most difficult thing when implementing this service is pairing the numbering plans of the trunking network and the PSTN.
As for the data transmission function, to implement it it is best to focus on specialized data transmission terminals or radio stations equipped with an RS232 interface. Using modems in analog radio networks is not a cheap pleasure.
Where is the number?
In Europe they are already beginning to forget about analog communications (largely thanks to the efforts of Dolphin). In our Fatherland, they are only looking closely at the numbers.
In August, the St. Petersburg operator RadioTel, part of the Telecominvest holding, announced the beginning of the creation of a test zone for trunked digital communications in the TETRA standard. Its launch was scheduled for early September. In Russia, this is already the second experimental area of digital trunking communications: the first was deployed in the St. Petersburg metro, where ELETTRA equipment (TETRA standard) from the transnational concern Marconi was used.
The RadioTel company intends to use Motorola equipment in the test zone. One BS and 20 portable and car radio stations will operate here. To demonstrate the possibility of international TETRA-GSM roaming, the issue of connecting a BS via a dedicated channel to one of the PBXs in Denmark or Germany is being considered. Testing in St. Petersburg will last three months, after which Motorola will dismantle the equipment and transfer it for testing to another Russian partner, who has not yet been selected.
RadioTel is the operator of the only digital radio access system in Russia, EDACS, produced by Ericsson. Today, according to RadioTel, its services are used by approximately 1,600 subscribers, including Ambulance, Lenvodokanal and the Administration of St. Petersburg. The latter built on the basis of this network the Unified System of Operational Trunking Communications (ESOTR).
Let’s hope that the “ice has broken,” gentlemen, readers, and digital trunking networks will still appear in Russia. Perhaps, in just six months, potential users of this type of communication will be interested in the nomenclature and characteristics not of analog simplex walkie-talkies, but of modern digital trunking “tubes”.
Trunking radio communication systems, which are radial-area mobile VHF radio communication systems that automatically distribute repeater communication channels between subscribers, are a class of mobile communication systems focused primarily on the creation of various departmental and corporate communication networks, which provide for the active use of the mode connections of subscribers in the group. They are widely used by security and law enforcement agencies, public security services of various countries to ensure communication between mobile subscribers among themselves, with landline subscribers and subscribers of the telephone network.
There are a large number of different standards for trunked public mobile radio communication systems (SPR-OP), differing from each other in the method of transmitting voice information (analog and digital), the type of multiple access (FDMA - frequency division channels, TDMA - time division channels or CDMA - with code division of channels), method of searching and assigning a channel (with decentralized and centralized control), type of control channel (dedicated and distributed) and other characteristics.
Currently, both in the world and in Russia, the previously appeared analog trunking radio communication systems, such as SmarTrunk, MPT1327 protocol systems (ACCESSNET, ACTIONET, etc.), Motorola systems (Startsite, Smartnet, Smartzone), systems with distributed control channel (LTR and Multi-Net from E.F.Johnson Co and ESAS from Uniden). The most widely used systems are MPT1327, which is explained by the significant advantages of this standard compared to other analog systems.
It should be said that in Russia, the majority of large trunking networks are built on the basis of equipment of the MPT1327 standard. Managers of companies involved in the supply of equipment and system integration in the field of professional radio communications note that most of the operational voice communication tasks facing their customers are quite effectively solved using analog systems of the MPT1327 standard.
Digital standards for trunked radio communications have not yet become so widespread in Russia, but we can already talk about their active and successful implementation.
At the same time, the circle of users of digital trunking systems is constantly expanding. Large customers of professional radio communication systems are also emerging in Russia, whose requirements are driving the transition to digital technologies. First of all, these are large departments and corporations, such as RAO UES, the Ministry of Transport, the Ministry of Railways, Sibneft and others, as well as security forces and law enforcement agencies.
The need for the transition is explained by a number of advantages of digital trunking over analog systems, such as greater spectral efficiency due to the use of complex types of signal modulation and low-speed speech conversion algorithms, increased capacity of communication systems, equalization of the quality of voice exchange throughout the base station service area due to the use of digital signals in combination with noise-resistant coding. The development of the global market for trunked radio communication systems today is characterized by the widespread introduction of digital technologies. The world's leading manufacturers of trunking system equipment are announcing the transition to digital radio communication standards, providing for either the release of fundamentally new equipment or the adaptation of analogue systems to digital communication.
Digital trunking systems have a number of advantages over analogue ones due to the implementation of the requirements for increased efficiency and security of communications, the provision of wide possibilities for data transmission, a wider range of communication services (including specific communication services to implement the special requirements of public security services), and the possibility of organizing interaction subscribers of various networks.
1. High efficiency of communication. First of all, this requirement means the minimum possible time for establishing a communication channel (access time) for various types of connections (individual, group, with telephone network subscribers, etc.). In conventional communication systems, when transmitting digital information that requires time synchronization of the transmitter and receiver, it takes longer to establish a communication channel than an analog system. However, for trunked radio communication systems, where information exchange is mainly carried out through base stations, the digital mode is comparable in access time to analog (in both analog and digital radio communication systems, as a rule, the control channel is implemented based on digital signals).
In addition, digital trunking radio communication systems more easily implement various communication modes that increase its efficiency, such as direct communication mode between mobile subscribers (without using a base station), open channel mode(allocation and assignment of network frequency resources to a specific group of subscribers for further negotiations without performing any installation procedure, including without delay), emergency and priority call modes, etc.
Digital trunking radio communication systems are better adapted to various modes of data transmission, which provides, for example, law enforcement officers and public safety services with ample opportunities to quickly obtain information from centralized databases, transmit the necessary information, including images, from incident sites, and organize centralized dispatch location systems mobile objects based on satellite radio navigation systems. These systems allow consumers of the oil and gas complex to use them as transport not only for the transmission of voice communications, but also for the transmission of telemetry and telecontrol.
2. Data transfer. Digital trunking radio communication systems are better adapted to various data transmission modes, which provides subscribers of digital networks with ample opportunities to quickly obtain information from centralized databases, transmit the necessary information, including images, and organize centralized dispatch systems for locating moving objects based on satellite radio navigation systems. The data transfer rate in digital systems is much higher than in analogue ones.
Most radio communication systems based on digital standards implement services for the transmission of short and status messages, personal radio calls, fax communications, and access to fixed communication networks (including those operating based on TCP/IP protocols).
3. Communication security. Includes requirements for ensuring the secrecy of negotiations (precluding the possibility of extracting information from communication channels to anyone other than an authorized recipient) and protection against unauthorized access to the system (precluding the possibility of seizing control of the system and attempts to disable it, protection from “doubles” and etc.). As a rule, the main mechanisms for ensuring communication security are encryption and subscriber authentication.
Naturally, in digital radio communication systems, compared to analogue systems, it is much easier to ensure communication security. Even without taking special measures to conceal information, digital systems provide an increased level of protection for conversations (analog scanning receivers are not suitable for listening to conversations in digital radio communication systems). In addition, some digital radio standards provide for end-to-end encryption of information, which allows the use of original (i.e., user-developed) speech closure algorithms.
Digital trunking radio communication systems allow the use of a variety of subscriber authentication mechanisms: various identification keys and SIM cards, complex authentication algorithms using encryption, etc.
4. Communication services. Digital trunking systems implement a modern level of service for subscribers of communication networks, providing opportunities for automatic registration of subscribers, roaming, data flow control, various modes of priority call, call forwarding, etc.
Along with standard network service functions, at the request of law enforcement agencies, digital trunking radio communication standards often include requirements for the availability of specific communication services: call mode, received only with the approval of the system dispatcher; mode of dynamic modification of user groups; mode for remotely switching on radio stations for acoustic listening of the environment, etc.
5. Possibility of interaction. Digital radio communication systems, which have a flexible structure for addressing subscribers, provide ample opportunities both for creating various virtual networks within one system, and for organizing, if necessary, interaction between subscribers of different communication networks. For public security services, the requirement to ensure the possibility of interaction between units of various departments to coordinate joint actions in emergency situations: natural disasters, terrorist attacks, etc. is especially relevant.
The most popular digital trunking radio communication standards that have earned international recognition, on the basis of which communication systems have been deployed in many countries, include:
- EDACS, developed by Ericsson;
- TETRA, developed by the European Telecommunications Standards Institute;
- APCO 25, developed by the Association of Public Safety Communications Officials;
- Tetrapol, developed by Matra Communication (France);
- iDEN developed by Motorola (USA).
All these standards meet modern requirements for trunked radio communication systems. They allow you to create various configurations of communication networks: from the simplest local single-zone systems to complex multi-zone systems at the regional or national level. Systems based on these standards provide various modes of voice transmission (individual communication, group communication, broadcast call, etc.) and data (switched packets, circuit-switched data transmission, short messages, etc.) and the ability to organize communication with various systems using standard interfaces (with a digital network with integration of services, with a public telephone network, with private automatic telephone exchanges, etc.). Radio communication systems of these standards use modern speech conversion methods combined with effective methods of noise-resistant information coding. Radio manufacturers ensure that they comply with MIL STD 810 standards for various climatic and mechanical influences.
2. General information about digital trunking radio communication standards
2.1. SystemEDACS
One of the first digital trunking radio communication standards was the EDACS (Enhanced Digital Access Communication System) standard, developed by Ericsson (Sweden). Initially, it provided only analog speech transmission, but later a special digital modification of the EDACS Aegis system was developed.
The EDACS system operates in accordance with a proprietary protocol that meets the security requirements for the use of trunked radio communication systems, which have been developed by a number of mobile equipment manufacturers in conjunction with law enforcement agencies (APS Document 16).
Digital EDACS systems were produced in the frequency ranges 138-174 MHz, 403-423, 450-470 MHz and 806-870 MHz with a frequency spacing of 30; 25; and 12.5 kHz.
EDACS systems use frequency division communication using a high-speed (9600 bps) dedicated control channel, which is intended for the exchange of digital information between radio stations and system control devices. This ensures high efficiency of communication in the system (the time to establish a communication channel in a single-zone system does not exceed 0.25 s). The information transmission speed in the working channel also corresponds to 9600 bps.
Speech coding in the system is carried out by compressing a pulse-code sequence at a speed of 64 Kbit/s, obtained using analog-to-digital signal conversion with a clock frequency of 8 kHz and a bit width of 8 bits. The compression algorithm, which implements the adaptive multi-level coding method (developed by Ericsson), provides dynamic adaptation to the individual characteristics of the subscriber's speech and generates a low-speed digital sequence, which is subjected to noise-resistant coding, bringing the digital stream speed to 9.2 Kbps. Next, the generated sequence is divided into packets, each of which includes synchronization and control signals. The resulting sequence is transmitted into the communication channel at a speed of 9600 bps.
The main functions of the EDACS standard, providing the specifics of public safety services, are various call modes (group, individual, emergency, status), dynamic call priority control (up to 8 priority levels can be used in the system), dynamic modification of subscriber groups (regrouping), remote shutdown radio stations (in case of loss or theft of radio equipment).
EDACS standard systems provide the ability to operate radio equipment in both digital and analogue modes, which allows users at a certain stage to use the old fleet of radio communication equipment.
One of the main objectives of the system development was to achieve high reliability and fault tolerance of communication networks based on this standard. This goal was achieved, as evidenced by the reliable and stable operation of communication systems in various regions of the world. High fault tolerance is ensured by the implementation of a distributed architecture in the EDACS system hardware and the underlying principle of distributed data processing. The base station of the communication network remains operational even if all repeaters fail, except one. The last operational repeater in this case initially operates as a control channel repeater; when calls arrive, it processes them, assigning its own frequency channel, and then switches to operating channel repeater mode. If the base station controller fails, the system goes into emergency mode, in which some network functions are lost, but partial functionality remains (repeaters operate autonomously).
In the EDACS system, end-to-end encryption of information is possible, however, due to the closed protocol, it is necessary to use either a standard security algorithm offered by Ericsson, or agree with it on the possibility of using its own software and hardware modules that implement original algorithms that must be compatible with the EDACS system protocol.
Today, a large number of EDACS standard networks have been deployed around the world, including multi-zone communication networks used by public security services in various countries. There are about ten networks of this standard operating in Russia, the largest is the communication network of the Federal Protective Service of Russia in Moscow, which includes 9 base stations. At the same time, Ericsson is currently not working to improve the EDACS system, has stopped supplying equipment for the deployment of new networks of this standard and only supports the functioning of existing networks.
2.2 TETRA system
TETRA is a digital trunked radio standard consisting of a number of specifications developed by the European Telecommunications Standards Institute (ETSI). The TETRA standard was created as a single pan-European digital standard. Therefore, until April 1997, the acronym TETRA stood for Trans-European Trunked RAdio. However, due to the great interest shown in the standard in other regions, its coverage is not limited to Europe. TETRA currently stands for Terrestrial Trunked Radio.
TETRA is an open standard, meaning that equipment from different manufacturers is expected to be compatible. Access to TETRA specifications is free to all interested parties who have joined the TETRA Memorandum of Understanding and Promotion Association (MoU TETRA). The association, which included more than 80 members at the end of 2001, brings together developers, manufacturers, testing laboratories and users from various countries.
The TETRA standard consists of two parts: TETRA V+D (TETRA Voice+Data) - a standard for an integrated voice and data transmission system, and TETRA PDO (TETRA Packet Data Optimized) - a standard describing a special version of a trunking system focused only on data transmission .
The TETRA standard includes specifications for the wireless interface, interfaces between the TETRA network and the integrated services digital network (ISDN), public switched telephone network, data network, private branch exchanges, etc. The standard includes a description of all basic and additional services provided by networks TETRA. Interfaces for local and external centralized network management are also specified.
The TETRA radio interface assumes operation in a standard frequency grid with a step of 25 kHz. The required minimum duplex spacing of radio channels is 10 MHz. For TETRA systems, some frequency subbands can be used. In European countries, security services are assigned the ranges 380-385/390-395 MHz, and for commercial organizations the ranges 410-430/450-470 MHz are provided. In Asia, TETRA systems use the range 806-870 MHz.
TETRA V+D systems use Time Division Multiple Access (TDMA) communication channels. Up to 4 independent information channels can be organized on one physical frequency.
Messages are transmitted in multiframes with a duration of 1.02 s. The multiframe contains 18 frames, one of which is a control frame. The frame has a duration of 56.67 ms and contains 4 time slots. In each time interval, information of its own time channel is transmitted. The time interval has a length of 510 bits, of which 432 are informational (2 blocks of 216 bits).
TETRA standard systems use relative phase modulation of the p/4-DQPSK type (Differential Quadrum Phase Shift Keying). Modulation speed - 36 Kbps.
To convert speech, the standard uses a codec with a CELP (Code Excited Linear Prediction) type conversion algorithm. The bit rate at the codec output is 4.8 Kbps. Digital data from the output of the speech codec is subjected to block and convolutional coding, interleaving and encryption, after which information channels are formed. The throughput of one information channel is 7.2 Kbit/s, and the speed of the digital information data flow is 28.8 Kbit/s. (In this case, the total transmission rate of symbols in the radio channel due to additional service information and a control frame in the multiframe corresponds to the modulation rate and is equal to 36 Kbit/s.)
TETRA standard systems can operate in the following modes:
- trunking communication;
- with open channel;
- direct connection.
In mode trunking communication the serviced area overlaps with the coverage areas of base transceiver stations. The TETRA standard allows both using only a distributed control channel in systems, and organizing its combination with a dedicated frequency control channel. When a network operates with a distributed control channel, service information is transmitted either only in a multiframe control frame (one of 18), or in a specially allocated time channel (one of 4 channels organized on the same frequency). In addition to the distributed one, the communication network can use a dedicated frequency control channel, specifically designed for the exchange of service information (in this case, maximum communication services are realized).
In mode with open channel a group of users has the ability to establish a “one point - multiple points” connection without any installation procedure. Any subscriber, having joined the group, can use this channel at any time. In open channel mode, radio stations operate in a dual-frequency simplex.
In mode direct (direct) connection Point-to-point and multipoint connections are established between terminals via radio channels not associated with the network control channel, without transmitting signals through base transceiver stations.
In TETRA standard systems, mobile stations can operate in the so-called. “Dual Watch” mode, which ensures the reception of messages from subscribers operating in both trunking and direct communication modes.
To increase service areas, the TETRA standard provides for the possibility of using subscriber radio stations as repeaters.
TETRA provides users with a number of services that are included in the standard at the request of the European Police Association (Schengen Group), collaborating with the ETSI technical committee:
- call authorized by dispatcher(a mode in which calls are received only with the approval of the dispatcher);
- priority access(in case of network congestion, available resources are assigned according to a priority scheme);
- priority call(assigning calls in accordance with the priority scheme);
- priority interrupt call service(interruption of service for low priority calls if system resources are exhausted);
- selective listening(interception of an incoming call without affecting the work of other subscribers);
- remote listening(remotely switching on a subscriber radio station to transmit to listen to the subscriber’s situation);
- dynamic regrouping(dynamic creation, modification and deletion of user groups);
- calling party identification.
The TETRA standard provides two levels of security for transmitted information:
- standard level, which uses radio interface encryption (providing a level of information security similar to the GSM cellular communication system);
- high level, using end-to-end encryption (from source to recipient).
TETRA radio interface security features include mechanisms for authenticating the subscriber and the infrastructure, ensuring traffic confidentiality through a flow of pseudonyms and specified encryption of information. A certain additional protection of information is provided by the ability to switch information channels and control channels during a communication session.
A higher level of information security is a unique requirement for special user groups. End-to-end encryption ensures voice and data protection at any point along the communication line between landline and mobile subscribers. The TETRA standard specifies only an interface for end-to-end encryption, thereby providing the ability to use original information security algorithms.
It should also be noted that in the TETRA standard, in connection with the use of time division channel (TDMA) communication in all subscriber terminals, it is possible to organize communication in full duplex mode.
TETRA networks are deployed in Europe, North and South America, China, Southeast Asia, Australia, and Africa.
Currently, the development of the second stage of the standard (TETRA Release 2 (R2)), aimed at integration with 3rd generation mobile networks, a radical increase in data transfer speed, the transition from specialized SIM cards to universal ones, further increasing the efficiency of communication networks and expanding possible service areas.
In Russia, TETRA equipment is offered by a number of system integrator companies. Several pilot projects of TETRA networks have been implemented. Under the auspices of the Ministry of Communications, the development of a system project “Federal Mobile Radio Communications Network TETRA”, called “Tetrarus”, is being developed. In 2001, the Russian TETRA Forum was created, whose tasks include promoting TETRA technology in Russia, organizing the exchange of information, promoting the development of national production, participating in the work on harmonizing the radio frequency spectrum, etc. In accordance with the decision of the State Committee for Energy and Energy of 07/02/2003 d. the use of the TETRA standard is recognized as promising “... in order to provide communications to government bodies of all levels, defense, security, law enforcement, the needs of departments and large corporations.”
2.3. APCO 25 system
The APCO 25 standard was developed by the Association of Public Safety Communications Officials-international, which unites users of public safety communications systems.
Work on creating the standard began at the end of 1989, and the last documents to establish the standard were approved and signed in August 1995 at the APCO International Conference and Exhibition in Detroit. Currently, the standard includes all the main documents that define the principles of constructing the radio interface and other system interfaces, encryption protocols, speech coding methods, etc.
In 1996, it was decided to divide all specifications of the standard into two implementation phases, which were designated Phase I and Phase II. In mid-1998, functional and technical requirements for each of the phases of the standard were formulated, emphasizing the new capabilities of Phase II and its differences from Phase I.
The fundamental principles for the development of the APCO 25 standard, formulated by its developers, were the following requirements:
- to ensure a smooth transition to digital radio communications (i.e., the possibility of joint work at the initial stage of standard base stations with subscriber analog radio stations currently used);
- to create an open system architecture to stimulate competition among equipment manufacturers;
- to ensure the possibility of interaction between various units of public security services when conducting joint events.
The system architecture of the standard supports both trunked and conventional (conventional) radio communication systems, in which subscribers interact with each other either in direct communication mode or through a repeater. The main functional block of the APCO 25 standard system is the radio subsystem, defined as a communication network that is built on the basis of one or more base stations. Moreover, each base station must support the Common Radio Interface (CAI - Common Radio Interface) and other standardized interfaces (intersystem, PSTN, data port, data network and network management).
The APCO 25 standard provides the ability to operate in any of the standard frequency ranges used by mobile radio systems: 138-174, 406-512 or 746-869 MHz. The main method of access to communication channels is frequency-based (FDMA), however, according to Ericsson's application, Phase II includes the possibility of using time division multiple access (TDMA) in APCO 25 standard systems.
In Phase I, the standard frequency grid step is 12.5 kHz, in Phase II - 6.25 kHz. At the same time, with a 12.5 kHz band, four-position frequency modulation is carried out using the C4FM method at a speed of 4800 symbols per second, and with a 6.25 kHz band, four-position phase modulation with phase smoothing is carried out using the CQPSK method. The combination of these modulation methods allows the use of identical receivers in different phases, supplemented by various power amplifiers (for Phase I - simple amplifiers with high efficiency, for Phase II - amplifiers with high linearity and a limited width of the emitted spectrum). In this case, the demodulator can process signals using any of the methods.
Speech information in the radio channel is transmitted in 180 ms frames, grouped into 2 frames. For speech coding, the standard uses the IMBE (Improved MultiBand Excitation) codec, which is also used in the Inmarsat satellite communication system. Encoding speed - 4400 bps. After noise-resistant coding of speech information, the speed of the information flow increases to 7200 bit/s, and after the formation of speech frames by adding service information - up to 9600 bit/s.
The subscriber identification system incorporated in the APCO 25 standard allows you to address at least 2 million radio stations and up to 65 thousand groups in one network. In this case, the delay when establishing a communication channel in the subsystem in accordance with the functional and technical requirements for the APCO 25 standard should not exceed 500 ms (in direct communication mode - 250 ms, when communicating through a repeater - 350 ms).
APCO 25 systems, in accordance with functional and technical requirements, must provide 4 levels of cryptographic protection. A stream method of information encryption is used using nonlinear algorithms for generating an encryption sequence. When using a special OTAR (Over-the-air-re-keying) mode, encryption keys can be transmitted over the air.
Due to the fact that the main method of accessing communication channels in APCO is MDIR, there are currently no terminals that would provide subscriber operation in full duplex mode.
Despite the fact that APCO is an international organization with offices in Canada, Australia, and the Caribbean, American firms supported by the US government play the main role in promoting this standard. The Association's public sector members include the FBI, the US Department of Defense, the Federal Communications Committee, the police of several US states, the Secret Service and many other government organizations. Leading companies such as Motorola (the main developer of the standard), E.F. Johnson, Transcrypt, Stanlite Electronics, etc. have already declared themselves as manufacturers of APCO 25 standard equipment. Motorola has already presented its first system based on the APCO 25 standard, called ASTRO.
Specialists from the Russian Ministry of Internal Affairs show the greatest interest in this standard. A pilot network (not yet trunking, but conventional radio communication) based on two base stations was deployed by the Russian Ministry of Internal Affairs in Moscow in 2001. In 2003, in St. Petersburg, for the 300th anniversary of the city, a dispatch radio network for 300 subscribers was deployed in the interests of various security forces.
2.4. Tetrapol system
Work on the creation of the Tetrapol digital trunking radio communication standard began in 1987, when Matra Communications entered into a contract with the French gendarmerie to develop and commission the Rubis digital radio communication network. The communication network was put into operation in 1994. According to Matra, today the network of the French gendarmerie covers more than half of the territory of France and serves more than 15 thousand subscribers. Also in 1994, Matra created its Tetrapol forum, under the auspices of which the Tetrapol PAS (Publicly Available Specifications) specifications were developed, defining the standard for digital trunked radio communications.
The Tetrapol standard describes a digital trunked radio communication system with a dedicated control channel and a frequency separation method for communication channels. The standard allows you to create both single-zone and multi-zone communication networks of various configurations, also providing the possibility of direct communication between mobile subscribers without using network infrastructure and relaying signals on fixed channels.
Tetrapol standard communication systems have the ability to operate in the frequency range from 70 to 520 MHz, which, in accordance with the standard, is defined as a combination of two sub-bands: below 150 MHz (VHF) and above 150 MHz (UHF). Most of the radio interfaces for systems in these subbands are common; the difference lies in the use of different methods of noise-resistant coding and code interleaving. In the UHF sub-band, the recommended duplex spacing of receive and transmit channels is 10 MHz.
The frequency spacing between adjacent communication channels can be 12.5 or 10 kHz. In the future, it is planned to move to a spacing between channels of 6.25 kHz. Tetrapol standard systems support a bandwidth of up to 5 MHz, which makes it possible to use 400 (at 12.5 kHz spacing) or 500 (at 10 kHz spacing) radio channels in the network. In this case, from 1 to 24 channels can be used in each zone.
The information transmission speed in the communication channel is 8000 bit/s. Information transmission is organized in frames with a length of 160 bits and a duration of 20 ms. The frames are combined into superframes with a duration of 4 s (200 frames). The information undergoes complex processing, including convolutional coding, interleaving, scrambling, differential coding and final frame formatting.
Tetrapol standard systems use GMSK modulation with BT=0.25.
To convert speech, the standard uses a codec with a speech conversion algorithm that uses the RPCELP (Regular Pulse Code Excited Linear Prediction) analysis method. The conversion speed is 6000 bps.
The standard defines three main communication modes: trunking, direct communication mode and relay mode.
IN network mode(or trunking mode) interaction between subscribers is carried out using base stations (BS), which distribute communication channels between subscribers. In this case, control signals are transmitted on a separate frequency channel specially allocated for each BS. In direct communication mode, information is exchanged between mobile subscribers directly without the participation of a base station. IN relay mode communication between subscribers is carried out through a repeater, which has fixed channels for transmitting and receiving information.
Tetrapol standard systems support 2 main types of information exchange: voice transmission and data transmission.
Voice Services Allows you to make the following types of calls: broadcast call, open channel setup call, group call, individual call, multiple call using subscriber list, emergency call.
Data services provide a number of application level services supported by functions embedded in radio terminals, such as inter-subscriber messaging in accordance with the X.400 protocol, access to centralized databases, access to fixed networks in accordance with the TCP/IP protocol, fax transmission, file transfer, transmission of personal call signals, transmission of short messages, transmission of status calls, support for the transmission mode of object location data obtained using GPS receivers, transmission of video images.
The Tetrapol standard provides standard network procedures that provide a modern level of subscriber service: dynamic regrouping, subscriber authentication, roaming, priority calling, control of the subscriber's transmitter, control of the subscriber's "profile" (remote change of the parameters of the subscriber radio terminal embedded in it during programming), etc.
Tetrapol standard systems provide users with a number of additional services, which, along with the provision of maintenance services, make it possible to effectively implement specific communication networks for public security services and law enforcement agencies. Such services include access priority (providing preferential access to the system when radio communication channels are overloaded); priority call (assigning calls according to a priority scheme); priority scanning (providing a user belonging to several groups with the opportunity to receive calls from a subscriber in any of the groups); call authorized by the dispatcher (a mode in which calls are received only with the approval of the communications network dispatcher); call forwarding (unconditional call forwarding to another subscriber or forwarding if the called subscriber is busy); connecting to a call (enabling a mode in which one user interacting with another can make a third party a participant in the connection); selective listening (interception of an incoming call without affecting the work of other subscribers); remote listening (remotely switching on a subscriber radio station to transmit to listen to the subscriber’s situation); calling party identification (determining and displaying the calling party identifier on the called subscriber's terminal); “dual surveillance” (the ability of a subscriber radio terminal operating in network mode to also receive messages in direct communication mode) and many others.
Due to the fact that from the very beginning the Tetrapol standard was focused on meeting the requirements of law enforcement agencies, it provides various mechanisms for ensuring communication security aimed at preventing threats such as unauthorized access to the system, eavesdropping on ongoing conversations, creating intentional interference, traffic analysis specific subscribers, etc. Such mechanisms include:
- automatic network reconfiguration(periodic redistribution of communication network resources (configuration changes) due to the installation and cancellation of open channels, dynamic regrouping, reassignment of communication channels by the network manager, etc.);
- system access control(control of access to communication network equipment using smart cards and a password system);
- end-to-end encryption of information(ensuring the ability to protect transmitted information at any point on the communication line between subscribers);
- subscriber authentication(automatic or at the request of the network manager authentication of subscribers);
- use of temporary subscriber IDs(replacement of unique identification numbers of subscribers with pseudonyms, changed with each new communication session);
- imitation of radio subscriber activity(mode of supporting constant traffic during a break in negotiations by sending signals to the BS via communication channels that are difficult to distinguish from information ones);
- remote shutdown of the radio terminal(the ability to disable the subscriber radio terminal by the network manager);
- distribution of keys via radio channel(the ability for the network manager to transmit secret keys to subscribers over a radio channel).
Tetrapol standard systems are widely used in France. Apparently, not without the support of the government of the domestic manufacturer, in addition to the Rubis communication network of the national gendarmerie, Tetrapol systems are operated by the French police (Acropolе system) and the railway service (Iris system).
The Tetrapol standard is also popular in some other European countries. Based on this standard, communication networks of the police of Madrid and Catalonia, security units of the Czech Republic, and airport services in Frankfurt have been deployed. A special Matracom 9600 communications network is being deployed for the benefit of the Berlin transport company. Communication network radio stations will be installed on more than 2000 buses of the enterprise. In addition to radio communications, the network uses the function of determining the location of vehicles.
In 1997, Matra Communications won a tender to create a digital radio communications system for the Royal Thai Police. The contract is part of an order to modernize the police radio network, which will connect 70 police stations. It is expected to use the most modern system capabilities, including access to a centralized database, e-mail, end-to-end encryption of information, location determination. There are also reports of several systems being deployed in two other Southeast Asian countries, as well as for Mexico City police.
Tetrapol standard systems are not yet used in our country. Currently, FAPSI intends to deploy an experimental area of trunking radio communications of this standard in Russia.
2.5. SystemiDEN
iDEN (integrated Digital Enhanced Network) technology was developed by Motorola in the early 90s. The first commercial system based on this technology was deployed in the United States by NEXTEL in 1994.
In terms of standard status, iDEN can be characterized as an enterprise standard with an open architecture. This means that Motorola, while retaining all rights to modify the system protocol, also licenses the production of system components to various manufacturers.
This standard was developed to implement integrated systems that provide all types of mobile radio communications: dispatch communications, mobile telephone communications, transmission of text messages and data packets. iDEN technology is aimed at creating corporate networks of large organizations or commercial systems that provide services to both organizations and individuals.
When implementing mobile radio dispatch networks, iDEN provides group and individual calling capabilities, as well as a call signaling mode in which, if a subscriber is unavailable, the call is stored in the system and then transferred to the subscriber when he becomes available. The number of possible groups in iDEN is 65535. The connection establishment time for a group call in half-duplex mode does not exceed 0.5 s.
iDEN systems provide the ability to organize telephone communication in any direction: mobile subscriber - mobile subscriber, mobile subscriber - PSTN subscriber. Telephone communication is fully duplex. The system provides voice mail capabilities.
Subscribers of iDEN systems have the opportunity to send and receive text messages to their terminals, as well as transfer data (in switching mode at a speed of 9.6 Kbit/s, and in packet mode - up to 32 Kbit/s), which makes it possible to organize fax communications and electronic mail, as well as interaction with fixed networks, in particular the Internet. Packet data transfer mode supports the TCP/IP protocol.
The iDEN system is based on MDVR technology. Each 25 kHz frequency channel carries 6 speech channels. This is achieved by dividing a 90 ms frame into 15 ms time intervals, each of which transmits information on its own channel.
For speech coding, a codec is used that operates using a VSELP type algorithm. The information transmission rate in one channel is 7.2 Kbit/s, and the total speed of the digital stream in the radio channel (due to the use of noise-resistant coding and the addition of control information) reaches 64 Kbit/s. Such a high information transmission rate in a 25 kHz band can be achieved through the use of 16-position quadrature modulation M16-QAM.
The standard uses the standard frequency range for America and Asia 805-821/855-866 MHz. IDEN has the highest spectral efficiency among the considered digital trunking communication standards; it allows up to 240 information channels to be placed in 1 MHz. At the same time, the size of the coverage areas of base stations (cells) in iDEN systems is smaller than in systems of other standards, which is explained by the low power of subscriber terminals (0.6 W for portable stations and 3 W for mobile ones).
The iDEN system architecture has features typical of both trunked and cellular systems, which emphasizes iDEN's focus on serving a large number of subscribers and intense traffic. When creating commercial systems to serve various organizations or enterprises, up to 10,000 virtual networks can be created in the system, each of which can have up to 65,500 subscribers, united, if necessary, into 255 groups. In this case, each group of subscribers can use the entire communication area provided by this system.
The first commercial system, deployed in 1994 by NEXTEL, is now nationwide with approximately 5,500 sites and 2.7 million subscribers. There is another network in the US, operated by Southern Co. iDEN networks are also deployed in Canada, Brazil, Mexico, Colombia, Argentina, Japan, Singapore, China, Israel and other countries. The total number of iDEN subscribers in the world today exceeds 3 million people.
iDEN systems have not been deployed in Russia and there is no information about the development of network projects of this standard.
3. Brief comparative analysis of digital radio communication standards
3.1. Specifications and functionality
General information about the EDACS, TETRA, APCO 25, Tetrapol, iDEN standards systems and their technical characteristics are presented in Table 1.
Table 1.
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The functionality provided by digital trunked radio standards systems is presented in Table 2.
Table 2.
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Note:(n/s - no information)
Considering the technical characteristics and functionality of the presented trunking communication standards, it can be noted that all standards have high (relative to this class of mobile radio communication systems) technical indicators. They allow you to build various configurations of communication networks, provide various modes of voice and data transmission, communication with PSTN and fixed networks. Radio communications of these standards use effective methods of speech conversion and noise-resistant coding of information. All standards ensure high communication efficiency.
It can be noted that compared to other standards, EDACS has slightly lower spectral efficiency. In addition, some experts note that the EDACS standard does not use digital modulation methods, which allows us to speak of it as a standard in which digitized speech information is transmitted over an analog communication channel.
In terms of functionality, the EDACS standard is, perhaps, also to a certain extent inferior to the other three standards, since it was developed somewhat earlier. The TETRA, APCO 25, Tetrapol and iDEN standards specify a wide range of standard communication services provided, comparable in level to each other. (As a rule, the list of services provided is determined when designing a specific radio communication system or network.)
3.2. Meeting special requirements for public safety radio communications systems
Information on the availability of some specific communications services targeted at use by public safety officials is presented in Table 3. The iDEN standard is not discussed here because this standard was not developed with the specific requirements of public safety agencies in mind. Currently, only isolated information appears about ongoing attempts to adapt systems of this standard to special requirements.
Table 3.
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Since the standards presented in the table were developed in the interests of public safety services, they all ensure the fulfillment of most of the requirements for special communication systems, as can be seen in Table 2. The presented digital standards ensure high communication efficiency (access time for all systems is no more than 0 ,5 c) and provide opportunities to increase the fault tolerance of radio communication networks through a flexible architecture. All standards make it possible to implement information security: for TETRA and Tetrapol systems, the standards provide for the possibility of using both a standard encryption algorithm and original algorithms through end-to-end encryption; in EDACS systems, you can use a standard proprietary algorithm or specifically agree with the company on the possibility of using your own protection system; in accordance with the functional and technical requirements for systems of the APCO 25 standard, 4 levels of information protection must be provided (of which only one can be intended for exported applications).
When considering the list of special communication services provided by each standard, it can be noted that the TETRA, APCO 25, Tetrapol standards provide a comparable level of special services, while EDACS provides a slightly lower level. The iDEN standard is not intended to meet special requirements.
3.3. Radio spectrum resources
The availability of radio frequency spectrum (RFS) resources for the deployment of a radio communication system is the most important criterion for choosing a particular system. In this case, the most promising standards are those that provide the ability to build communication networks in the widest range.
EDACS systems are implemented in the bands 138-174, 403-423, 450-470 and 806-870 MHz, and there is information about existing radio networks in all bands.
TETRA systems assume the use of the following ranges: 380-385/390-395, 410-430/450-470 MHz and 806-870 MHz.
APCO 25 systems, in accordance with the functional and technical requirements, provide the ability to operate in any of the ranges allocated for mobile radio communications.
The Tetrapol standard limits the top frequency of its systems to 520 MHz.
iDEN standard systems operate only in the 800 MHz range, which limits their use for building a certain range of systems.
It should be noted that the allocation of radio frequency spectrum resources for the construction of digital trunking radio communication systems is most realistic in the 400 MHz range.
3.4. Standard status (open/closed)
When choosing a radio standard, it is imperative to consider whether the standard is open or enterprise (closed).
Corporate standards (EDACS and Tetrapol) are the property of their developers. Purchasing equipment is possible only from a limited range of manufacturers.
Open standards, which include TETRA and APCO 25, ensure the creation of a competitive environment, attracting a large number of manufacturers of basic equipment, subscriber radio stations, and test equipment to produce compatible radio equipment, which helps reduce their cost. Access to standard specifications is provided to any organizations and firms that have joined the appropriate association. Users who choose an open radio standard are not dependent on a single manufacturer and can change equipment suppliers. Open standards are supported by government and law enforcement agencies, large companies in many countries around the world, and are also supported by the world's leading manufacturers of components and components.
Conclusion
A brief comparative analysis of these digital trunking radio communication standards according to the main criteria considered allows us to draw certain conclusions about the prospects for their development both in the world and in Russia.
The EDACS standard has virtually no prospects for development. Compared to other standards, it has lower spectral efficiency and less extensive functionality. Ericsson has no plans to expand the capabilities of the standard and has practically curtailed equipment production.
The iDEN standard does not provide many special requirements, and, despite its high spectral efficiency, is limited by the need to use the 800 MHz band. It is likely that systems of this standard have some potential and will continue to be deployed and operated, particularly in the Americas. In other regions, the prospects for deploying systems of this standard look dubious.
The Tetrapol standard has good technical performance and sufficient functionality, but, like the EDACS and iDEN standards, it does not have the status of an open standard, which can significantly hinder its development in technical terms, as well as in terms of the cost of subscriber and fixed equipment.
The TETRA and APCO 25 standards have high technical characteristics and broad functionality, including meeting the special requirements of law enforcement agencies, and have sufficient spectral efficiency. The most important argument in favor of these systems is the availability of open standards status.
At the same time, most experts are inclined to believe that the digital trunking radio market will be conquered by the TETRA standard. This standard enjoys wide support from most of the world's major equipment manufacturers and communications administrations in various countries. Recent events in the domestic professional radio communications market allow us to conclude that in Russia this standard will become more widespread.
Trunk connection
In the modern business world, more and more attention is paid to mobile communications: pagers, cellular and satellite communications devices, personal communicators and similar devices. Indeed, in order to be competitive, modern companies need to constantly maintain communication with their customers, and, just as importantly, between the employees of their organization. Recently, some mobile operators have been offering so-called “corporate” tariffs (for example, the MTS corporate program), which are specifically designed to create a “virtual telephone network” for company employees. However, such programs are not the cheapest solution to the communication problem, but, fortunately, not the only possible one.
For a company that decides to “connect” its mobile employees, there is an alternative solution - the use of trunk communication. Perhaps many readers are seeing the phrase “trunk connection” for the first time. Indeed, trunk communication systems are now receiving less attention than even paging systems. To some extent, this is due to the fact that trunk communication systems are intended primarily for use by large organizations, and not by mass users. Despite this, this technology has its merits and deserves to be considered in this article.
So, what is hidden behind the term “trunk system”? Paradoxically, we use it every day without even thinking about it. It is on the principle of trunking that the operation of modern automatic telephone exchanges is based. Let's see what happens when you try to call, say, your friend from your home phone. You pick up the phone, wait for the “line free” signal, then dial the number and wait for an answer. All other actions are performed by the PBX: it selects one of the free communication channels and switches (links) your telephone set with the telephone set of a friend. At the end of the conversation, the line that was used is released and becomes available for use by other people. As you might guess, the number of communication lines is limited and is certainly less than necessary to connect all telephone sets in the city. Thus, the PBX controls the distribution of a limited number of lines among a large number of subscribers. It is assumed that a situation where all subscribers suddenly decide to contact each other at the same time will not arise. Therefore, it is necessary to correctly calculate the minimum required number of communication channels so that problems associated with their shortage do not arise during the work process. This issue is effectively solved using the mathematical theory of queuing systems.
Rice. 1. In trunk telephony, the subscriber simply dials a number, and the PBX allocates a free line through which a conversation can be carried out.
What is a trunked radio system?
Trunk radio systems are mobile radio communication systems that are based on the same principles as conventional telephone networks. In other words, in a trunk radio communication system there is a limited number of radio channels (usually from two to twenty), which are allocated by the central controller for negotiations as needed.
Fig.2. In trunked radio systems, the subscriber requests permission to talk, and a central controller (consisting of several repeaters) allocates a channel on which the conversation can be carried out.
In conventional radio communication systems, the user has to manually retune to a free radio channel; in trunk communication systems, this work is undertaken by the central controller, which itself allocates a free channel to two radio stations. Thus, the user just needs to dial the number of the called subscriber, and the system will do the rest itself. A trunk system can be defined as follows: Automatic and dynamic distribution of a small number of channels among a large number of radio users.
Fig.3. Load diagram of a five-channel trunk system. The bottom graph shows cases of call blocking when all five channels of the system are busy.
Areas of application of trunk radio communication systems.
Now, knowing the basic principles of operation of trunk systems, let's talk a little about their areas of application and the advantages of using them. Areas of application - large commercial and government organizations, for example, traffic inspection services, various repair services, companies specializing in the field of industrial mountaineering (maintenance of high-rise buildings) and so on. A trunk communication system can be deployed both in a large city and in a remote, sparsely populated area, which is especially important in the conditions of our country. Trunk systems effectively use the frequency band allocated to them, provide a high level of confidentiality (there are even tools that allow you to encode speech during its transmission), are reliable, and provide a large number of service functions. Finally, perhaps their greatest advantage is that the organization itself can become the owner of a trunk radio communication system, freeing itself from subscription fees and traffic fees.
Types of trunk radio communications.
It's time to understand the types of trunk communication. Various companies and organizations have developed a huge number of trunk communication formats, many of which are incompatible with each other. In the USA, the most popular formats are Privacy Plus, developed by Motorola, Logic Trunked Radio - LTR, manufactured by E.F. Johnson, as well as SmarTrunk II from SmarTrunk Systems, formerly known as Selectone. Also noteworthy is Motorola's iDEN project, which offers a digital trunk communication format. In Europe, the MPT1327 standard, developed in England for public radio networks, has become widespread. Now this standard has become popular in Asia, Australia, and Latin American countries. Currently, work is underway in Europe to create a new European protocol for digital trunk systems - TETRA (Trans European Trunked Radio).
In Russia, the most well-known protocols are SmarTrunk II, MPT1327, LTR.
If we classify trunk systems according to the number of subscribers, we can distinguish three groups:
- small, in which the number of subscribers does not exceed 300 people. When building such systems, the SmarTrunk II protocol is used;
- medium-sized, the number of subscribers does not exceed 3,000 people. Most often, when creating such systems, the LTR standard is used;
- large, with a number of subscribers exceeding 3000 people. In this case, the MPT 1327 protocol is most often used.
MPT1327 and TETRA are classified as open protocols, while LTR, SmartNet, etc. - to the class of closed, “branded” ones, however, both of them work according to two basic principles, which we will consider in the next part of the article.
Comparison of trunking methods.
Currently, there are two methods for managing trunk systems. The first is distributed control, the second is control over a dedicated channel.
The dedicated channel method has several disadvantages compared to the distributed control method. One of them is that when using a dedicated channel, all requests are carried out with its participation, therefore, it is necessary to somehow avoid collisions when transmitting data. Another disadvantage is that a system with a dedicated channel must process requests sequentially, and as the load increases and the number of available channels decreases, the number of requests grows exponentially, so that mobile devices are forced to fight each other for a single channel.
One of the advantages of the distributed control method is that access can be obtained via any currently free channel. Repeaters determine an open channel and transmit this information in a data stream that exists together with voice information. This means that each repeater maintains its own data flow and processes all requests on its own channel. Collision processing is performed by mobile devices, which ensures parallel processing of calls.
Another advantage of the distributed control method is that the voice data is transmitted over all channels, whereas in the dedicated channel method the control channel generally cannot be used in this way. The figure shows the locking speed of a five-channel system compared to the locking speed of a four-channel system (one channel is used for control). It can be seen that the blocking time of the five-channel system is significantly less.
Fig.4. Blocking time comparison.
Typically, in trunk systems, idle time (the time between two adjacent transmissions) is not used in negotiations. The channel is held only for the duration of the transmission, and the time between transmissions can be used by other people making calls. And only during telephone conversations the channel is held permanently.
Some trunking systems take advantage of downtime in negotiations during busy periods. This allows the called party to almost always answer the call without fear of being blocked. The obvious disadvantage of this approach is an increase in the total transmission time and, consequently, an increase in the probability of blocking and waiting time for other subscribers.
Access priority is a setting that determines who gets access to a busy system first. Most systems with a dedicated control channel use a method that allows all mobile devices to try to gain access, but denies the channel to devices with a lower priority level. In distributed control systems, all mobile devices have the same priorities, and no device can access the system while the channel is busy. When a channel becomes free, the device that first tries to occupy the line gets access to it.
Mobile devices used in trunk communication systems must be programmed to operate on a specific frequency (usually 800 or 900 MHz); many functions (eg channel selection, channel check before transmission) are performed automatically.
Each repeater can have up to 250 ID codes associated with it. The ID code and home repeater number form the address of the mobile device on the network. Thus, in a system containing 20 repeaters, the maximum number of subscribers is 5000. The ID code can be assigned to either one mobile device or several at once.
Block diagram of a base station for a trunk radio communication system.
Figure 5 shows a block diagram of a base station in the case of using one channel.
The repeater consists of a repeater designed to receive signals from subscriber radio stations, amplify and transmit them, and a trunk channel controller that performs control functions.
Duplex filter is a device that allows you to use one antenna for reception and transmission. In principle, nothing prevents you from using two different antennas for reception and transmission, but in this case a situation may arise when reception is possible in some places, but transmission is not possible, or vice versa. In addition, the power emitted by the transmitter affects the receiver, so if you have two antennas, they must be installed at a sufficient distance from each other.
The power supply is for the repeater. Typically, it allows for the ability to switch to battery power when the power is lost.
The considered scheme is quite simple and effective, but in real conditions one trunk channel is not enough. Therefore, systems containing two or more channels are used. The figure shows a diagram of a system containing four independent channels. As you can see, the main difference from the previous version is in the antenna-feeder path, where two more devices appear: the receiving distribution panel and the combiner.
The receive distribution panel provides the same input signal to each repeater in the system, as if the repeater were connected directly to the antenna.
A combiner is a device that allows you to combine the outputs of a certain number of transmitters without interference with each other.
An uninterruptible power supply is also provided separately, which simply must be present in the system, because the lack of communication in emergency circumstances can lead to unpredictable consequences.
The considered system is easy to expand, that is, if designed correctly, the number of channels can be increased quite painlessly.
Review of radiotelephone models.
Currently, equipment for base stations and subscriber devices for trunk radio communication systems are produced by a large number of companies. Of these, the most famous are Motorola, Nokia, Ericsson, SmarTrunk Systems and others. As an example, let's look at several models of radiotelephones produced by Nokia.
Nokia H85.
Nokia H85 is a lightweight (weighs only 345 g with battery, output power 1 W in duplex mode), convenient radiotelephone for use in MPT 1327 systems. The device has a large, high-contrast alphanumeric display (contains 3 lines of 10 characters each) with voltage level indicators fields and battery charge. Access to numerous functions and settings of the device is carried out using the menu. H85 supports individual and group calls, calls over the public telephone network. The radiotelephone's memory can store up to 99 names and numbers of subscribers. There is also one programmable button that can be assigned to either your most frequently dialed number or an emergency number.
This device comes with a wide range of accessories, including a cigarette lighter charger and a dashboard holder. There are two types of chargers: desktop and portable.
Nokia R40.
Nokia R40 is a universal half-duplex radio station for users of trunk systems (weight 1.8 kg, output power 10 (15) W). The radio complies with MPT 1327 and MPT 1343 specifications, and the R40 also supports the MAP 27 data interface.
The radio station can be used both in a car and in a desktop version. The CU 43 alphanumeric console has 22 keys and a three-line, 100-character LCD display and allows you to make all possible types of calls on the radio network. Additionally, the console allows you to receive and transmit status messages and data. The on-screen menu is used to control the station. You can store up to 43 names and numbers of subscribers in memory.
The CU 45 communicator has a built-in digital LCD display, microphone and loudspeaker. Control is carried out using four function keys.
Peripheral devices, such as a data modem, can be connected to the radio via the MAP 27 interface.
Nokia R72.
Nokia R72 is a radiotelephone for working in MPT 1327/1343 networks (weight 1.8 kg, output power 10 W in full-duplex mode and 15 W in half-duplex mode). In addition to voice communication, a radiotelephone provides the ability to transmit and receive encoded messages and data.
The phone is convenient to use in the car. When the charging cable is connected to the cigarette lighter socket, the battery is automatically charged. The phone has a memory for 97 names and numbers of subscribers, and also allows you to program up to nine speed dial numbers. In addition, the phone has a number of other features, including the transmission of tones to connect to telephone network equipment, the use of an encrypted sequence number (ESN) and lock codes to protect against unauthorized access.
You may have noticed that the R72 looks exactly the same as the famous Nokia 720 - a mobile phone for use in NMT 450 networks. And the names of these two devices show that they have a lot in common.
Conclusion.
Having defined the main purpose of trunk radio communication, reviewed and compared its standards, studied the principles of constructing a central controller and, finally, familiarized ourselves with some models of radio stations, we have gained a general understanding of what trunk radio communication systems are. It should be noted that at present they continue to actively develop, new standards and equipment are being developed. The number of trunk communication systems designed and put into operation is growing every year. They certainly have a future.
For those who are interested in the topic discussed, I provide links to some resources on the Internet dedicated to trunk communication issues. At the end of the article there is also a glossary of terms used when describing trunk radio communication systems.
Links.
http://members.dingoblue.net.au/~activemedia/trnklinks.htm - Collection of links to resources dedicated to trunk systems.
http://www.sotovik.ru/analit.htm - The library on Sotovik contains a very large amount of materials on mobile communications, including a section dedicated to trunk systems.
Glossary.
Base station- a group of repeaters connected to the same data bus and located in one place.
Home repeater- all radio stations in a trunk radio communication system have one of the repeaters located at the base station as a “home” one. The radio station monitors this repeater to receive calls and receive information about which repeaters are available.
Duplex- a mode in which you can speak and listen at the same time (that is, receive and transmit).
Controller (Central Controller)- a computer that ensures the joint operation of all repeaters. Each repeater contains a controller. They are connected to each other using a data bus.
Mobile device- a transceiver installed in a car or a portable radio station.
Repeater- a device that receives and relays a radio signal. If you are using a five-channel trunk system, you will need five repeaters. One repeater can handle only one conversation at a time.
Simplex- a mode in which either transmission or reception is possible.
Trunking- Automatic and dynamic distribution of a small number of channels among a large number of radio users.
Control channel- one of the radio channels that is used to communicate with all mobile devices and to distribute service information.
Trunking communication systems are classified according to the following criteria [1].
By method of transmitting speech information: analog and digital. Speech transmission in the radio channel of analogue systems is carried out using frequency modulation; the frequency grid step is usually 12.5 kHz or 25 kHz. To transmit speech in digital systems, various types of vocoders are used, converting an analog speech signal into a digital one at a speed of no more than 4.8 kbit/s;
Depending on the number of base stations (BS) and the general architecture: single-zone or multi-zone systems. In systems of the first type there is one BS, in systems of the second type there are several BS with the possibility of roaming;
By the method of combining BS in multi-zone systems. BS can be combined using a single switch (centralized switching system), or connected to each other directly, or through distributed switching systems;
According to the method of searching and assigning a channel: systems with decentralized (SDU) and centralized (SCU) control. In the SDS, the procedure for searching for a free channel is performed by subscriber radio stations (AR). In these systems, BS repeaters (RTs) are usually not connected to each other and operate independently. Repeaters are a transceiver device operating in duplex mode. In frequency division trunking systems, there is one repeater for each working channel, the receiver and transmitter operate at different frequencies. A special feature of SDS is the relatively long time it takes to establish a connection between subscribers, which increases with the number of RTs. This dependence is caused by the fact that APs are forced to continuously scan channels sequentially in search of a calling signal (the latter can come from any RT) or a free channel (if the subscriber himself sends the call). Representatives of this class are systems of the SMARTRUNK I I standard
In the control center, the search and assignment of a free channel is carried out at the BS. To ensure the normal functioning of such systems, a control channel is organized. Its main function is to establish a connection between two network subscribers. All requests for communication are sent over the control channel; through the same channel, the BS notifies subscriber devices about the channel assignment, rejection of the request, or queuing of the request. Control channels are digital, in which data is transmitted at speeds up to 9.6 kbit/s.
4. Principles of building trunking networks
Figure 1 shows a generalized block diagram of a single-zone trunking communication system.
Block diagram of a single-zone trunking system.
Picture 1
The BS, in addition to radio frequency equipment (repeaters, antenna radio signal combining device), also includes a switch, a control device (CU) and interfaces to various external networks.
Repeater (RT) is a set of transceiver equipment serving one pair of carrier frequencies. In most trunked communication systems, one pair of carriers means one traffic channel (CT). With the advent of digital standards that provide temporary compaction, one RT can provide two or four CTs.
BS antennas, as a rule, have a circular radiation pattern. When the BS is located at the edge of the zone, directional antennas are used. The BS can have either a single transceiver antenna or separate antennas for reception and transmission. In some cases, multiple receive antennas may be placed on a single mast to combat multipath fading.
The radio signal combining device allows the use of the same antenna equipment for simultaneous operation of receivers and transmitters on several frequency channels.
The switch in a single-zone trunked communication system serves all its traffic, including the connection of mobile subscribers (MA) with the public switched telephone network (PSTN) and all calls associated with data transfer.
The control device (CU) ensures the interaction of all BS nodes. It also processes calls, authenticates callers, maintains call queues, and makes entries in the time-based payment data block (DB). In some systems, the control system regulates the maximum permissible duration of a connection to the telephone network. Typically, two adjustment options are used: reducing the connection duration during predetermined peak hours, or adaptively changing depending on the current load.
The interface to the PSTN is implemented in trunking communication systems in various ways. In some systems (for example, SMARTRUNK I I), the connection is made via a two-wire switched line. More modern trunked communication systems include direct dialing (DID) equipment as part of the interface to the PSTN, which provides access to trunked network subscribers using standard PBX numbering.
Connection to the PSTN is traditional for trunked communication systems, but recently the number of applications involving data transfer has been increasing, and therefore the presence of an interface to packet switching networks (PSN) is also becoming mandatory.
The maintenance and operation terminal (TOE) is usually located at the BS. The terminal is designed to monitor the state of the system, diagnose faults, charge, and make changes to the subscriber database (DB). Mandatory elements of trunking communication systems are dispatch consoles (DP). Trunking communication systems are used primarily by consumers of railway services and departments, the work of which requires the presence of an IF, ECH, and PM dispatcher. Shch, as well as security services, emergency medical services, fire protection, municipal services. DPs can be included in the system via subscriber radio channels, or connected via dedicated channels directly to the BS switch. Within the framework of one trunking communication system, several independent communication networks can be organized. Users of each of these networks will not notice the work of their neighbors and will not be able to interfere with the work of other networks. Therefore, several DPs connected to it in different ways can operate in one trunked communication system.
User equipment of trunk communication systems includes a wide range of devices. As a rule, the most numerous are half-duplex PCs, since they are most suitable for working in closed groups. Basically, these are functionally limited devices that do not have a numeric keypad. Their users have the opportunity to communicate only with subscribers within their workgroup, as well as send emergency calls to the dispatcher. As a rule, this is quite sufficient for most consumers of communication services of trunked radio communication systems. There are also half-duplex PCs with a wide range of functions and a numeric keypad, but they, being significantly more expensive, are intended for a narrower circle of subscribers.
In trunking communication systems, a new class of subscriber devices is gradually being used - duplex PCs, which resemble cell phones, but have significantly greater functionality compared to duplex PCs. Duplex radio stations of trunking communication systems provide users not only with a connection to the PSTN, but also with the ability to group work in half-duplex mode.
Both half-duplex and full-duplex trunking PCs are available not only in portable, but also in mobile versions. The output power of mobile PC transmitters is higher.
A relatively new class of devices for trunking communication systems are data terminals (TD). In analog training communication systems, PD terminals are specialized radio modems that support the corresponding radio interface protocol. For digital systems, it is more typical to integrate the PD interface into ARs of various classes. The mobile PD terminal often includes a satellite navigation receiver of the Global Position System (GPS), designed to determine current coordinates and subsequently transmit them to the dispatcher on the console.
In trunking communication systems, stationary PCs are also used, mainly for connecting DPs. The output power of stationary PC transmitters is approximately the same as that of mobile PCs.
The architecture of multi-zone trunking communication systems can be built according to two principles. If the determining factor is the cost of equipment, interzonal switching is used (Fig. 2).
Block diagram of a trunking network with distributed interzonal switching
Figure 2
Each BS in such a system has its own connection to the PSTN. If it is necessary to call from one zone to another, it is made through the PSTN interface, including the telephone number procedure. In addition, BSs can be directly connected using physical leased lines.
The use of distributed inter-zonal switching is advisable only for systems with a small number of zones and with low requirements for the efficiency of inter-zonal calls (especially in the case of connections via switched PSTN channels). High quality of service systems use a central switch (CS) architecture. The structure of a multi-zone trunking communication system with a central control center is shown in Fig. 3.
Block diagram of a trunking network with centralized interzonal switching
Figure 3
The main element of this scheme is the interzonal switch. It handles types of inter-area calls i.e. all inter-zonal traffic passes through one switch connected to the BS via dedicated lines. This ensures fast call processing and the ability to connect centralized dispatch centers. Information about the location of subscribers of a centralized payment system is stored in a single place, so it is easier to protect. In addition, the interzonal switch also performs the functions of a centralized interface to the PSTN and UPC, which allows, if necessary, complete control of both the voice traffic of the telephone network and the traffic of all PD applications associated with external UPC, such as the Internet. Thus, a system with a central control system has higher controllability.
"I affirm"
Chairman of the Committee on Informatization and Communications
_________________
"___" _____________ 200___
VOLUME 3
DOCUMENTATION ABOUT THE AUCTION
TO CONDUCT AN OPEN AUCTION FOR THE RIGHT TO CONCLUSION OF A ST. PETERSBURG STATE CONTRACT FOR THE PROVISION OF TRUNKING RADIO COMMUNICATION SERVICES AND DATA TRANSMISSION SERVICES
FOR USERS OF A UNIFIED SYSTEM OF OPERATIONAL TRUNKING RADIO COMMUNICATION
FOR THE NEEDS OF EXECUTIVE BODIES OF STATE AUTHORITY OF ST. PETERSBURG
TECHNICAL TASK
Section 1. General requirements
1. Auction item, initial (maximum) contract price
1. The subject of this auction is the right to conclude a contract for
provision of trunking radio communication services and data transmission services to users of the unified operational trunking radio communication system (ESOTR) for the needs of executive bodies of state power in St. Petersburg.
2. Initial (maximum) contract price 29 ,00 rubles
3. Codes according to the All-Russian Classifier of Types of Economic Activities of Products and Services (OKDP) corresponding to the auction item: 6420050.
2 . Objectives and legal basis for the provision of services
1. The purpose of providing services is to guarantee the provision of operational radio communications to city government bodies, their subordinate enterprises and services, special-purpose services related to ensuring the safety of citizens and urban infrastructure, in compliance with the vital interests of the individual, society and the state, with prevention, prevention and prompt response to emergency situations.
2. The grounds for the provision of services are Orders of the Governor of St. Petersburg dated 01/01/01 No. 49-P “On the creation of a unified operational trunking radio communication system for the needs of the Administration of St. Petersburg” and dated 01/01/01 No. 50-P “On the development of a unified operational trunking radio communication systems for the needs of the Administration of St. Petersburg."
3. Source of financing for the state order of St. Petersburg
Source of financing for the state order of St. Petersburg: the budget of St. Petersburg for 2010 in accordance with the Law of St. Petersburg dated ________ No. __________ “On the budget of St. Petersburg for ____ year and for the planning period ____ and _____ years”, target article 3300030 “Expenditures” for the operation and development of a unified operational trunking radio communication system,” economic article 221 “Communication services.”
4. Form, terms and procedure for payment for services
1. Form of payment: payment is made in non-cash form in accordance with the approved budget allocations.
2. Terms and procedure for payment: payment is made quarterly on the basis of the issued invoice, invoice and the certificate of services provided signed by the parties within 5 working days.
3. Advance payments are not provided.
5. Place, conditions and terms (periods) of provision of services
1. Place of provision of services: the territory of the city of St. Petersburg and its nearest suburbs.
2. Conditions and terms (periods) for the provision of services: from January 1, 2010 to December 31, 2010.
6. The procedure for forming the contract price
1. The initial (maximum) price of the contract is formed: on the basis of monitoring the prices of telecom operators providing services in the Russian Federation.
2. The contract price is formed by the participant on the basis of the calculation of the initial (maximum) price attached by the customer, taking into account the costs of delivery, customs duties, taxes and other obligatory payments.
Stationary
Stationary
Duty unit N-W of the Internal Affairs Directorate for transport of the Ministry of Internal Affairs of the Russian Federation
Stationary
Stationary
Duty department 5 Directorate 8 Ch. Department of the Ministry of Internal Affairs of the Russian Federation
Stationary
Duty department Main. Managed execution of punishments
Stationary
The duty unit of the FSB Directorate for St. Petersburg. and Len. region
Stationary
Stationary
Directorate of the FSB of the Russian Federation for the St. Petersburg region
Automotive
Automotive
Office of Government Communications in the North-West Region
Stationary
Automotive
Security Directorate for the North-Western Federal District of the Federal Security Service of Russia
Stationary
Stationary
Leningrad Military District
Stationary
Stationary
Leningrad naval base St. Petersburg
Stationary
Stationary
Northwestern District of Internal Troops
Stationary
North-West Regional Directorate of the Federal Border Service of Russia
Stationary
Military commandant's office
Stationary
Stationary
Housing Committee
Stationary
Stationary
Stationary
Automotive
Stationary
Dispatcher of the State Enterprise "Fuel and Energy Complex of St. Petersburg"
Stationary
Stationary
Dispatcher of GGH "Lengaz"
Stationary
Stationary
Dispatcher of State Unitary Enterprise "Vodokanal SPb"
Stationary
Stationary
Stationary
State Enterprise "Petersburg Metro"
Stationary
SE "Pulkovo Airlines"
Stationary
OJSC "St. Petersburg transport company "Avtotrans"
Stationary
JSC "Sea Port of St. Petersburg"
Stationary
OJSC "North-Western Shipping Company"
Stationary
SE GBU VOLGOBALT
Stationary
State Sanitary and Epidemiological Surveillance Center
Stationary
Gosatomnadzor District of the Russian Federation
Stationary
Duty department of the Leningrad Military District Engineering Department
Stationary
North-West Territorial Administration for Hydrometeorology, Environmental Monitoring
Stationary
Stationary
Department of Natural Resources for the North-West Region (NW DPR)
Stationary
State Enterprise "Engineering Center for Environmental Works"
Stationary
TsUKS GUGOCHS
Stationary
Stationary
Stationary
PPU GUGOCHS
Stationary
PPU of the Governor of St. Petersburg (GUGOCHS)
Automotive
PPU of the head of GUGOCHS SPb
Automotive
ASS GUGOCHS duty officer
Stationary
Grandfather crew of ACC GUGOCHS SPb
Automotive
Head of GUGOCHS SPb
1st deputy Head of GUGOChS St. Petersburg
Deputy NGUGOCHS (on operational issues)
Deputy NGUGOCHS (operational defense)
Head of GUGOCHS St. Petersburg
Automotive
Deputy Head of GUGOChS for operational issues
Automotive
Deputy Head of the GUGOChS for protection
Automotive
Deputy Head of GUGOChS for training and education
Automotive
GUGOCHS duty vehicle
Automotive
1st Deputy Head of GUGOCHS
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
Automotive
ASS GUGOCHS car
Automotive
Rescuers ASS GUGOCHS
Operational group GUGOCHS
Department of teaching staff GUGOCHS
Communications Department GUGOCHS
Emergency Prevention Department of GUGOCHS
Department of emergency personnel at sea and water basins
Department of ITM GUGOCHS
RKhBZ Department of GUGOCHS
Medical department protection GUGOCHS
Evacuation and transport department of GUGOChS
Logistics Department GUGOCHS
Head of ACC GUGOCHS
Deputy Head of ACC GUGOCHS
Rescuers ASS GUGOCHS
Deputy Head of GUGOChS for logistics
Deputy Head of GUGOChS for training and education
Beginning Control GOChS Admiralteysky district
Beginning Control GOChS Vasileostvovsky district
Beginning Control GOChS Vyborg district
Beginning Control GOChS Kalininsky district
Beginning Control GOChS Kirovsky district
Beginning Control GOChS Kolpinsky district
Beginning Control GOChS Krasnogvardeisky district
Beginning Control GOChS Krasnoselsky district
Beginning Control GOChS Kronstadt district
Beginning Control GOChS of Kurortny district
Beginning Control GOChS Lomonosovsky district
Beginning Control GOChS Moscow region
Beginning Control GOChS Nevsky district
Beginning Control GOChS Pavlovsky district
Beginning Control GOChS Petrogradsky district
Beginning Control GOChS Petrodvortsovy district
Beginning Control GOChS Primorsky district
Beginning Control GOChS Pushkinsky district
Beginning Control GOChS Frunzensky district
Beginning Control GOChS of the Central district
Committee on Informatization and Communications
Automotive
Stationary
Automotive
Office of the Governor of St. Petersburg
Office of the Vice-Governor of St. Petersburg - Head of the Office of the Governor of St. Petersburg
Automotive
Stationary
Stationary
State Department Protocol of the Committee for External Relations of the St. Petersburg Administration
State Institution "TV Company "St. Petersburg Cable Television"
Stationary
Automotive
Administration of the Office of the Governor of St. Petersburg
Automotive
Department of Personnel and Civil Service of the Office of the Governor of St. Petersburg
Automotive
City Hospital No. 1
Stationary
City Hospital No. 3
Stationary
City Hospital No. 4
Stationary
City Hospital No. 14
Stationary
City Hospital No. 15
Stationary
City Hospital No. 16
Stationary
City Hospital No. 17
Stationary
City Hospital No. 26
Stationary
City Hospital No. 30
Stationary
VHP Clinic
Stationary
IVOV Hospital
Stationary
Institute of Emergency Medicine
Stationary
City Children's Hospital № 1
Stationary
Children's City Hospital No. 2
Stationary
Children's City Hospital No. 5
Stationary
Children's City Hospital No. 19
Stationary
Poison Control Center
Stationary
Health Committee
Stationary
Stationary
Ambulance depot
Automotive
Automotive
State Healthcare Institution "City Clinic No. 24"
Stationary
State Healthcare Institution "City Clinic No. 27"
Stationary
State Healthcare Institution "City Clinic No. 4"
Stationary
State Healthcare Institution "City Clinic No. 97"
Stationary
State Healthcare Institution "Children's City Clinic No. 11"
Stationary
State Healthcare Institution "City Clinic No. 23"
Stationary
State Healthcare Institution "City Clinic No. 43"
Stationary
State Healthcare Institution "City Clinic No. 17"
Stationary
State Healthcare Institution "City Clinic No. 93"
Stationary
GUZ "SSMP Kolpino"
Automotive
Stationary
State Healthcare Institution "Hospital No. 40"
Automotive
Stationary
State Healthcare Institution "City Clinic No. 21"
Stationary
State Healthcare Institution "City Clinic No. 47"
Stationary
State Healthcare Institution "City Clinic No. 46"
Stationary
State Healthcare Institution "City Clinic No. 8"
Stationary
State Healthcare Institution "City Clinic No. 32"
Stationary
State Healthcare Institution "City Clinic No. 000"
Stationary
State Healthcare Institution "City Clinic No. 000"
Stationary
State Healthcare Institution "City Clinic No. 37"
Stationary
Main Directorate for Civil Defense and Emergency Situations of St. Petersburg
Stationary
Stationary
Automotive
Automotive
GU TsUS FPS EMERCOM of the Russian Federation for St. Petersburg
Stationary
Automotive
City clinic No. 52
Stationary
City clinic No. 86
Stationary
City clinic No. 96
Stationary
City clinic No. 88
Stationary
City clinic No. 000
City clinic No. 000
Stationary
City clinic No. 48
City clinic No. 51
Stationary
SSMP Petrodvorets
Stationary
City clinic No. 000-2
Stationary
City clinic No. 56
Stationary
City clinic No. 19
Stationary
City clinic No. 44
Stationary
City clinic No. 38
Stationary
Chairman of the Commission under the Government of St. Petersburg for the prevention and response to emergency situations and ensuring fire safety
Automotive
Stationary
Total fixed radio stations
Total car radios
Total portable radios
TOTAL
2 328
1.2. Subscribers using subscription services during the first quarter of 2010:
|
Subdivision |
Model r/st |
Qty |
|
|
Administration of the Admiralteysky district | |||
|
Administration of Vasileostvovsky district | |||
|
Administration of the Vyborg region | |||
|
Administration of Kalininsky district | |||
|
Administration of the Kirov region | |||
|
Administration of Kolpinsky district | |||
|
Administration of Krasnogvardeisky district | |||
|
Administration of Krasnoselsky district | |||
|
Administration of Kronstadt district | |||
|
Administration of Kurortny district | |||
|
Administration of the Moscow region | |||
|
Administration of Nevsky district | |||
|
Administration of Petrogradsky district | |||
|
Administration of Petrodvortsovy district | |||
|
Administration of Primorsky district | |||
|
Administration of Pushkinsky district | |||
|
Administration of Frunzensky district | |||
|
Administration of the Central District | |||
|
TOTAL radio stations |
1.3. Subscribers using data transmission services in the operational trunking communication network of the TETRA standard:
|
No. |
Number of radio stations |
||
|
Administration of the Admiralteysky district of St. Petersburg | |||
|
Administration of Vasileostrovsky district of St. Petersburg | |||
|
Administration of the Vyborg district of St. Petersburg | |||
|
Administration of the Kalininsky district of St. Petersburg | |||
|
Administration of the Kirovsky district of St. Petersburg | |||
|
Administration of the Kolpinsky district of St. Petersburg | |||
|
Administration of Krasnogvardeisky district of St. Petersburg | |||
|
Administration of Krasnoselsky district of St. Petersburg | |||
|
Administration of the Kronstadt district of St. Petersburg | |||
|
Administration of the Kurortny district of St. Petersburg | |||
|
Administration of the Moskovsky district of St. Petersburg | |||
|
Administration of the Nevsky district of St. Petersburg | |||
|
Administration of the Petrogradsky district of St. Petersburg | |||
|
Administration of the Petrodvortsovy district of St. Petersburg | |||
|
Administration of the Primorsky district of St. Petersburg | |||
|
Administration of Pushkinsky district of St. Petersburg | |||
|
Administration of the Frunzensky district of St. Petersburg | |||
|
Administration of the Central District of St. Petersburg | |||
|
Department of Duty Service of the Governor's Office of St. Petersburg | |||
|
Housing Committee | |||
|
Energy and Engineering Committee | |||
|
Committee for Improvement and Road Maintenance | |||
|
Committee on Legality, Law and Order and Security, Department for Civil Defense, Emergency Situations and Fire Safety | |||
|
Main Directorate of Internal Affairs for St. Petersburg and Leningrad Region | |||
|
FSB Directorate for St. Petersburg and Leningrad Region | |||
|
State Institution "Transportation Organizer" | |||
|
Health Committee | |||
|
Hydrometeorological center | |||
|
TOTAL: |
1.4. Subscribers using data transmission services in the operational trunking communication network of the EDACS standard:
|
No. |
Name of institution, object |
Number of radio stations |
|
Department of duty service of the Administration of St. Petersburg | ||
|
Duty service of the Admiralteysky District Administration | ||
|
Duty service of the Administration of Vasileostvovsky district | ||
|
Duty service of the Vyborg District Administration | ||
|
Duty service of the Administration of Kalininsky district | ||
|
Duty service of the Kirov District Administration | ||
|
Duty service of the Kolpino District Administration | ||
|
Duty service of the Krasnogvardeisky District Administration | ||
|
Duty service of the Krasnoselsky District Administration | ||
|
Duty service of the Kronstadt District Administration | ||
|
Duty service of the Resort District Administration | ||
|
Duty service of the Moscow District Administration | ||
|
Duty service of the Nevsky District Administration | ||
|
Duty service of the Petrograd District Administration | ||
|
Duty service of the Administration of Petrodvorets district | ||
|
Duty service of the Primorsky District Administration | ||
|
Duty service of the Pushkin District Administration | ||
|
Duty service of the Frunzensky District Administration | ||
|
Duty service of the Central District Administration | ||
|
TsUKS GUGOCHS | ||
|
PPU GUGOCHS | ||
|
TOTAL: |
1.5. Trunking radio and data services
Appears in TETRA and EDACS standards;
Service provision is available around the clock (24 hours a day).
1.6. As part of the provision of radio communication services, users are provided with round-the-clock (24 hours a day) consultation on issues related to the operation of the ESOTP in the workplace or by telephone.
2. The specified services are provided in accordance with the cost calculation, calculation, which is an integral part of Volume 3 (Appendix).
8. Requirements for quality and safety of services
1. When providing services, the mobile radio communications operator’s network must ensure:
Possibility to use the Services around the clock, 7 (seven) days a week, days a year during the entire period of provision of services;
The quality of Services in the network coverage area is not lower than those provided for by the relevant technical conditions and standards throughout the entire period of provision of services;
The coverage area of the equipment should cover St. Petersburg and the nearest suburbs, Pulkovo Airport 1,2.
2. The mobile radio operator is obliged to:
Notify in advance (no later than three days in advance) the responsible persons of the departments using radio communication services about the implementation of maintenance activities, the implementation of which may lead to interruptions in the provision of services provided in accordance with this technical specification;
In case of detection of violations in the provision of services provided in accordance with this technical specification, and requiring more than three hours to eliminate them, not later than within three hours from the moment of detection of the violation, inform the responsible persons of the departments about this.
9. Requirements for technical characteristics of services
The services provided must meet the following requirements:
1. Support the operation of the following types of subscriber equipment:
EDACS standard: MDX, MDR, IPE System, IPE Scan, EP-4800, EM-4800 and analogues;
TETRA standard: SRH3500, SRM3500, STP8000, MTP850 and analogues.
2. Provide connection establishment time in group and individual half-duplex call modes of no more than 0.35 seconds;
3. Provide the following functionality of user equipment:
Support basic types of calls (individual, group, broadcast), direct communication mode, automatic registration of mobile subscribers, data transmission at speed (2.4 - 7.2 Kbps), transmission of status messages, transmission of short messages, emergency call;
Dividing all users into separate conversation groups (at least 100 groups);
Group calls between subscribers of all departments;
Emergency group (circular) calls - for all departments;
Individual (half-duplex) calls between subscribers of all departments;
Organization of communication schemes in accordance with the organizational and functional tasks of departments;
Possibility of interaction between subscribers of different organizational units in accordance with the established communication scheme.
4. Ensuring confidentiality within the organizational units of subscribers:
Blocking unauthorized switching of conversation channels;
Elimination of unauthorized connection to conversational channels and access to communication by extraneous means of communication.
10. Requirements for the results of services and other indicators related to determining the compliance of the services provided with the needs of the customer
At the end of each quarter, the Customer accepts the services provided, taking into account the shortcomings identified during the reporting period in the provision of services that are the subject of this contract.
Section 3. Requirements for the period and (or) volume of provision
service quality guarantees
1. When executing this Technical Specification (hereinafter referred to as the TOR) and the State Contract concluded under it (hereinafter referred to as the Contract), the Customer has the right to change the scope of all activities provided for in the TOR and the Contract for the provision of operational trunking radio communication services, but by no more than 10% of the Contract price, in case of identification of the need for additional measures not provided for by the ToR and the Contract, but not related to the measures for the execution of the ToR and the Contract, or if the need for part of the activities provided for by this ToR and the Contract ceases. At the same time, the Customer has the right to change the price of such a Contract in proportion to the volume of these additional activities but by no more than 10% of the Contract price
2. The Customer does not provide a period for providing a guarantee of the quality of trunked radio communication services and data transmission services.
Section 4. Requirements for the procedure for filling out the “Service Quality Proposal” form by the participant
1. If the technical (technological) solutions proposed by the participant, as well as materials (components and equipment) comply (identical) with the customer’s requirements set out in the technical specifications, the participant in column 3 of the form indicates the following “Services will be provided in accordance with all requirements, specified in the technical specifications using materials (components and equipment) specified in the technical specifications." Columns 1, 2 and 4 are not filled in by the participant.
2. If the participant proposes to use materials (components and equipment) other than those specified in the technical specifications, in column 3 of the form the participant must indicate all technical, quality and other characteristics that allow determining their equivalence (according to the indicators specified in the technical specifications task). Column 4 of the form indicates the brand name (brand, type, etc.), name of the manufacturer and country of origin, offered materials (components and equipment). Column 2 of the form contains a link to the relevant clauses of the technical specifications.
3. If the participant offers other technical (technological) solutions related to the provision of services, in column 3 of the form the participant indicates the relevant characteristics (description, indicators, etc.) that make it possible to determine the compliance of the services provided with the quality needs of the customer (according to the indicators specified in the technical specifications). Column 2 of the form contains a link to the relevant clauses of the technical specifications. Column 4 of the form is not filled out by the participant in this case.
Section 5. List of appendices to volume 3, which are its integral part.
Application
to the technical specifications
|
Item no. |
Type of service |
Number of subscribers |
Number of months |
Cost, rub. |
|
|
Per unit |
Total |
||||
|
1 |
2 |
4 |
5 |
6 |
7 |
|
|
1 055,00 | ||||
|
|
1 055,00 | ||||
|
Operational trunking radio communication services of the EDACS standard |
1 055,00 | ||||
|
|
1 000,00 | ||||
|
|
1 000,00 | ||||
|
Total: | |||||
|
including VAT (18%): |
* - based on monitoring prices of telecom operators providing services in the Russian Federation.
Application
to the technical specifications
to conduct an open competition for the right to conclude a government contract
St. Petersburg for the provision of trunking radio communication services and data transmission services for the unified operational trunking radio communication system (ESOTR)
|
Calendar plan for the provision of trunked radio communication services and data transmission services to users of the Unified System of Operational Trunked Radio Communications (USOTR) | |||||||
|
Reason: Volume 3 of the tender documentation for holding an open competition for the right to conclude a state contract of St. Petersburg for the provision of trunked radio communication services and data transmission services for the unified operational trunked radio communication system (ESOTR) | |||||||
|
Name |
Scope of services |
Schedule of services (quarters) |
|||||
|
Unit |
Cost, rub. | ||||||
|
1st quarter |
2nd quarter |
3rd quarter |
4th quarter |
||||
|
TETRA operational trunking radio communication services | |||||||
|
Operational trunking radio communication services of the EDACS standard | |||||||
|
Operational trunking radio communication services of the EDACS standard | |||||||
|
Data transmission services in the operational trunking communication network of the TETRA standard | |||||||
|
Data transmission services in the operational trunking communication network of the EDACS standard | |||||||
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