RU52293U1 - DISTRIBUTED MULTI-SERVICE TELECOMMUNICATION SYSTEM - Google Patents

Abstract

The utility model relates to the field of telecommunications, in particular, to build a subscriber network with the provision of various services to the subscriber. The technical result to which this utility model is directed is to improve the quality of the voice path in a multiservice telecommunication system. A distributed multiservice system based on a digital telephone exchange provides telephone traffic over a standard connection with a public switched telephone network, and at a subscriber site through an SCS transport structured cable network consisting of a fiber-optic communication line, remote subscriber access units, with subscriber analog terminals connected via copper twisted pairs, which are also used to access subscriber devices with the TCPMR protocol. The system is equipped with a connected digital telephone exchange and a router unit of digital multiplexers with optoelectronic transceivers, through individual fiber-optic lines connected to a fiber-optic communication line (FOCL). The latter is based on a multi-core fiber optic cable with optocross, and terminal subscriber units (VoLAN). Each unit is connected to the corresponding core of the fiber-optic cable and connected, Ethernet switches, personal computers and telephone subscriber terminals.

Description

The utility model relates to the field of telecommunications, in particular, to build a subscriber network with the provision of various services to the subscriber: telephony, data transmission, digital television, IP-telephony, video surveillance.

There are a large number of systems for the delivery of heterogeneous information to subscribers. However, in practice, the transport network of this information has become widespread in the form of a structured cable network (SCS), which is a combination of fiber optic communication lines (FOCL) on the trunk section, known in world practice as the "last mile" and copper multi-pair cable certain quality (twisted pair UTP). For direct connection of subscribers to this network, standard RJ-45 connectors are used for devices designed primarily for use in computer technology and RJ-11 connectors for connecting telephones, modems and faxes. A transport network, together with appropriate data transmission equipment, is known as a local area network (LAN).

Such local networks are capable of delivering to the subscriber a wide variety of information in digital form - data, the Internet, television, video and even voice traffic. These systems have recently been called "multiservice".

However, there is a problem of delivering voice information at a subscriber access site via a LAN.

This is due to the specifics of the speech schedule. For example, if data transfer, as a rule, is carried out in packets with non-guaranteed delivery time (the most popular TCP / IP protocol), followed by accumulation and assembly of files, then voice traffic requires a duplex transmission method and a guaranteed delivery time in order to avoid interruptions in the voice path. Otherwise, unpleasant phenomena such as “stuttering” and dips in the continuous speech signal are possible, which is unacceptable from the point of view of telephone conversation quality standards.

Known multiservice subscriber access systems that use only packet switching with bringing packets to the terminal devices for the telephone schedule in the form of special telephone sets (IP-telephones). These are quite complex and expensive devices that include coffee houses, microcontrollers with the implementation of a network protocol such as SIP, H323, etc. The transport protocol is also TCP / IP.

Such systems are produced by many well-known companies from Siemens, Mitel, Avaya, and others. The advantage of such systems is the uniformity of the information processed by universal packet switches, but a fast LAN is an essential condition for the functioning of such systems. With insufficient network performance, there are problems with the speech schedule, which are already mentioned above. Therefore, such systems are positioned mainly as platforms for the scale of office multiservice (including telephone) systems with a small number of users.

There are other ways to build multi-service subscriber access systems.

To get a high-quality speech schedule in many multiservice systems, many companies use automatic digital telephone exchanges (PBXs) or remote subscriber extensions, in combination with LAN.

Elements of structured cable networks are also used to deliver information to subscribers. To convert digital information from remote subscribers, subscriber adapters are used to connect various devices (terminals) to this network - analog telephones, digital telephones, computers, televisions, video monitors, IP phones, etc. In such systems, the presence of a digital telephone exchange can be clearly distinguished. , both for switching internal subscribers, and for interacting with the public switched telephone network (PSTN).

For example, a multiservice network with Internet access is offered by Olen Com (see. Company Directory). This solution is based on the use of an existing subscriber wiring already existing in a residential building or office. Multiservice is achieved by connecting subscribers to the LAN using free or additional regular telephone pairs to each subscriber. Access to the main Internet is through a separate access device (there may be technologies and equipment V.90, xDSL, ISDN, WLL.ADSL).

The disadvantages of such a network are obvious.

Firstly, a computer network implemented on a regular telephone pair with a claimed speed of 10 \ 100 Mbps does not meet modern standards and therefore reliable communication in such a network cannot be guaranteed.

Secondly, the proposed scheme generally does not provide subscribers with high-speed access to Ethernet, since the access of such a "home" network to the provider is through an access device with low-speed devices.

Asymmetric digital access technology (ADSL) for subscribers over telephone wires has the following disadvantages:

- quite expensive ADSL modems;

- there are restrictions on the length of subscriber lines and their condition;

- the speed of information transfer through ADSL is about 1 Mbps, which is a lot for speech, but clearly not enough for data.

When using fiber-optic communication lines, the point-to-point, ring, or a combination of these structures is most often used.

The main technology for building transport networks on fiber-optic lines is the ideology of a synchronous digital hierarchy (SDH), initially oriented to the transmission of telephone traffic (TDM), but recently supplemented by data transmission devices with speeds of 10 or 100 Mbit / s via Ethernet.

An example of such an integrated (multi-service) access system is the technology offered by AXXESSIT ASA (Norway) (see the company's advertising booklet, page 3. Fig. 1, 2, 4).

This system is designed for corporate subscribers and solves the problem of multiservice access on the fiber from office to office (FTTB) or fiber-central switchboard-office (FFTO) section, and the task of bringing information to the subscriber is solved through the use of office (office) PBX for telephone traffic and local area network (LAN) for IP traffic.

The closest analogue of the claimed utility model is a distributed multiservice telecommunication system consisting of a digital automatic telephone exchange (PBX) connected to a public switched telephone network (PSTN) and to the gateway equipment for accessing PBX subscribers via IP to IP-telephony network, a router with Internet access via a WAN broadband access line, a communication line from a router to a gateway (EP 0829995 A3, LAN telephone system, date of filing 09/16/1997), which implements a method for delivering telephone traffic and in batch form on a multiservice network. Telephone traffic is delivered to subscribers through a special unit called the Telephone Hub. This unit is connected to the LAN via the ATM interface in the Network Switch as a network device, which provides a packet-based method for exchanging packets in the ATM standard (Asynchronous Transfer Mode) with the network server. To form ATM packets, the Telephone Hub block has an ATM interface controller, a power supply, control logic, a digital signal processor (DSP), and

also standard telephone interfaces for connecting telephone sets (Patent Description, Figure 4.). The disadvantage of this solution is that the ATM packet interface is asynchronous, i.e. It works great in the field of data transfer, but voice traffic has the features mentioned above. ATM technology is not free from these shortcomings. In addition, in the above example, for connecting telephone sets, it is necessary to lay standard subscriber lines.

The technical result to which this utility model is directed is to improve the quality of the voice path in a multiservice telecommunication system.

The technical result is achieved by the fact that a distributed multiservice telecommunication system consisting of a digital automatic telephone exchange (PBX) connected to a public switched telephone network (PSTN) and to the gateway equipment for access of PBX subscribers via IP protocol to an IP-telephony network, a router with access to the Internet via a WAN broadband access line, a communication line from a router to a gateway, equipped with a connected digital telephone exchange and a router, a block of digital multiplexers with optoelectronic receivers by detectors connected via individual fiber-optic lines to a fiber-optic communication line (FOCL), based on a multi-core fiber optic cable with optocross, and terminal subscriber units (VoLAN), each of which is connected to the corresponding core of the fiber-optic cable and connected by Ethernet switches, personal computers and telephone subscriber terminals.

This technical solution allows you to create a multiservice system that provides high-quality communication at affordable costs and provide subscribers of this system with the ability to connect any modern digital communication equipment:

- analog telephone terminal;

- access to Ethernet at a speed of 10 \ 100 Mbps;

- IP telephony;

- digital television;

- video surveillance and fire alarm;

- monitoring of devices of housing and communal services.

Figure 1 shows the General structural diagram of the system.

Figure 2 shows the connection diagram of the terminal subscriber unit to the PBX and, further, to the router.

Figure 3 shows a block diagram of a subscriber terminal.

Figure 4 shows a block diagram of a digital telephone exchange.

A distributed multiservice telecommunication system consists of a digital automatic telephone exchange (PBX) 1, with external E1 standard streams for connecting to a public switched telephone network (PSTN) 9 and to gateway equipment 5 for access of PBX subscribers via IP to IP-network telephony, router 2 with access to the Internet 3 through a broadband access line WAN 4, communication lines 6-1 and 6-2, respectively, from router 2 to gateway 5 and to the unit of multiplexers 10 at a speed of 10 \ 100 Mb / s (Eth), with optoelectronic transceiver sensors, optical one- or two-core communication lines (Path-cord) 11-1-11-N, fiber-optic communication lines (FOCL) based on multi-core fiber-optic cable 13 with optocross 12, blocks of terminal multiplexers with terminal subscriber units (VoLAN) 14-1-14-N, standard Ethernet switches (Switch) 15-1-15-N, personal computers 16 and telephone subscriber terminals 17.

The system uses multichannel universal digital multiplexers 10, which allow combining from 10 to 20 independent duplex digital channels in a single optical path with a frequency of 0 to 50 Mbps each. At the same time, the transmission rate of information in the optical stream is 622 Mbps and 1,063 Gbps, respectively.

Such multiplexers based on the use of Fiber Channel technology (American standard ANSI INCITS 230) are produced by many companies as a component set (Chip set) or as a finished product ("MAXIM", "Hewlett-Packard", etc.) Standard digital streams E1 (2.048 Mb / s), Ethernet (10 \ 100 Mb / s), can be easily converted to standard logic levels with a pulse repetition rate of up to 50 MHz.

Through the multiplexer, working on Fiber Channel technology, digital streams 2/048 Mbit / s are transmitted directly in the ST-bus format (in Fig. 1. are indicated by the number 8). In this case, several 2.048 Mbit / s paths (from two to ten) are transmitted simultaneously with the simultaneous transmission of synchronization pulses and a clock frequency, which solves the problem of synchronization (framing) and allocation of the clock frequency on the receiving side.

As previously indicated, the digital streams in the standard St-bus and streams 100 Mbit / s on the station side are connected to the MX 10 multiplexers (See Figure 1).

The optical streams of the multiplexers 10 through the individual short optical communication lines 11 are connected to the corresponding cores of the fiber optic cable 13 in the fiber optic cable 12.

The next feature is the use of multicore fiber optic cable with a number of cores equal to the number of remote objects. This feature is illustrated in Figure 2.

The VoLAN 14 terminal subscriber unit is connected to the fiber optic cable through individual 19-1-19-N fibers (one or two, depending on the type of optical transceivers used). To make this connection, an optical coupler 18 is used. As can be seen from FIG. 2, the terminal subscriber unit uses the same fiber of the fiber-optic cable 13, moreover, one fiber is connected to the main terminal multiplexer 21 (fiber 19-1-OCH), and this is the fiber of the optical fiber cable 13 (19-1-REZ) is connected to the backup terminal multiplexer 22. In this case, a group of users (subscribers) of these remote objects is connected to the central switch according to the point-to-point scheme. This creates certain advantages both for telephony (the problem of "transit" is eliminated) and for access to the Ethernet network (segmentation).

Thanks to the use of Fiber Channel technology, heterogeneous digital information is delivered to directly end-user equipment in the form of a standard Ethernet for computer tasks and multimedia adapters, as well as telephone traffic in the form of an ST-bus interface.

In the proposed device, the fiber optic cable passes through all the remote user objects and forms a ring, but each object uses its own individual fiber (or a pair of fibers) and has access to the second, duplicate direction, which increases the reliability of the system and allows you to connect new objects or repair cable breaks without interruption in the work of subscribers. To implement the connection to the backup stream, the remote units incorporate two digital multiplexers - the main and the backup.

Thus, in the proposed scheme, information is transported via FOCL.

In addition to the fiber-optic multiplexers-transceivers 21 and 21, the VoLAN terminal subscriber unit contains an arbitrator electronic circuit whose purpose is to switch the internal ST-bus 27 buses and the internal parallel Ethernet 25 bus to the primary 21 or standby 22 multiplexer.

In the terminal subscriber unit (VoLAN) there is an Eternet 24 transceiver for converting the Ethernet 25 parallel bus to the IEEE 802.3 standard, i.e. 100 Base TX. This

the output of the VoLAN unit is connected to a standard lower-level local area network switch 15 (Switch), which provides for twisted pair connection directly to user devices using packet transmission of information via TCP / IP protocol.

To bring information flows to end users, a twisted pair of the category of the corresponding category (UTP-cat5) is used.

Connecting subscribers - users of telephone services in this technical solution differs from known solutions and proceeds as follows.

Directly in the VoLAN block 14 (Figure 2.) there are subscriber sets 28-1-28-N for converting speech signals into digital form and, conversely, from digital to analog. For this purpose, standard devices are used - coffee houses. For the operation of coffee-houses and the formation of the internal bus ST-bus 27 from the “frame” signal and a clock frequency of 2.048 MHz, temporary gates are formed for telephone channel intervals, coffee-houses for converting an analog speech signal into digital form. Thus, the conversion of digital telephone channels 64 Kbit / s into analog form with a frequency band of 3100 Hz.

The analog voice signal to the subscriber telephone terminals 17 (Fig. 1.) is transmitted through linear low-frequency transformers (Fig. 2. not shown). This device uses the so-called four-wire low-frequency telephone termination circuit.

The secondary windings of the transformers are connected to the subscriber wires of twisted pairs 27-1-27-N through splitters, 29-1-29-N, which effectively separate the signals of the digital interface 10 \ 100 Mbit \ sec., And analog signals with a band of 3100 Hz. Splitters are installed both on the transmission side and on the receiving side 31-1-31-N directly in the place of installation of blocks of custom sockets 30-1-30-N, in which RJ45 type connectors connected to the 32-1-32-N splitters are mounted -33-1-33-N) for connecting computer devices 16) and RJ11 34-1-34-N for telephone terminals.

This technical solution uses a specialized subscriber telephone terminal.

The peculiarity of this terminal is that the communication path of this terminal is built according to the four-wire termination scheme, but unlike the standard four-wire telephone, it uses the original power scheme of the active devices of this terminal.

The terminal contains an analog signal receiving path - incoming line 35, rectifier diode bridge 38 with storage capacitor, voltage converter of type “direct current to direct DC / DC) 39, comparator D1 40 with electronic relay K1, telephone capsule 37, key S1-1 36 , as well as a calling device in the form of an audio transformer ZP 42 and a key 41.

The analog signal transmission path consists of a key S1-2 46, an electronic dialer 44, a microphone 45, a summing amplifier 43 and an outgoing line 36. The terminal also includes a resistive voltage divider. Structurally, the telephone terminal is an ordinary telephone, but it has significant differences in circuitry and the principle of interaction with station equipment.

The telecommunication communication system operates as follows.

A transport network consisting of FOCLs, digital multiplexers with transceivers 10, Ethernet switches 15 and a subscriber cable network on a twisted pair cable is a standard solution of a local area network (LAN) and its operation does not require detailed explanations.

The operation of the telephone component in this network requires explanation.

Call processing, establishing connections with an external telephone network (PSTN) 9 is performed by a digital telephone exchange 1, which consists of a control controller 51 (see Fig. 4) containing the actual processor core MP, electronic memory of programs and semi-permanent data FLASH, random access memory RAM, digital switch 53, line cards of digital streams El (LIU) (Fig. 4, position 49.50), actually digital path lines 2.048 Mbps 54-1-54-N,

Internal digital streams 55 with the structure of the serial telecommunication bus "ST-bus", adopted as an internal standard in telephony by MITEL (Canada), generator equipment (not shown in the diagram).

In addition, the PBX includes digital signal processing (DSP) processors 47 and 48. The device uses a digital signal processor type ADSP2181 from ANALOG DEVICES. This type of processor provides processing of a group stream in the ST-bus format and interacts with the main processor 51 on a parallel bus. The digital PBX also includes a power supply 52, which provides power to all PBX devices

DSP signal processors are connected to the switch as follows. DSPs designed to handle signaling of external flows, e.g. 49 and 50,

connected to switch 53 in duplex mode and provide signaling processing in duplex mode.

The switch 53 is controlled via an internal parallel bus 55.

To service several external flows, a software resource and switching through a switch are used. DSP 48 signal processors that process subscriber signaling — generating service signals (station answer, busy, call control, etc.) are connected to the switch with their outgoing streams of 2.048 Mbps, and input streams of 2.048 Mbps all DSP subscriber signaling connected directly to the digital streams coming from the subscriber units VoLAN through multiplexers 21 and 22 (see Fig.2).

The software, which is recorded in the internal memory of the FLASH programs of the microcontroller 51, processes the signaling from external flows using standard algorithms, and the processing of subscriber signaling differs from the standard.

The subscriber terminal is powered by transmitting a sinusoidal signal with a frequency of 425 Hz, which is generated in digital form by a DSP processor, for example 48, and through the corresponding ST-bus stream, for example ST_BUS-3 (Figs. 4, 55), MX 10 multiplexer, corresponding coffee house of the subscriber end 28 (Figure 2) and then through the output transformer enters the subscriber terminal (Figure 3), to the rectifier 38. The power level of this signal is sufficient to power the DC \ DC 39 converter and comparator 40, and when lifting the handset subscriber terminal through con S1-1 cycles associated with the tube lifting mechanism, this signal is supplied to the telephone capsule, and the rectified voltage stabilized by the DC \ DC converter via pin S1-2 is supplied to the power circuit of the electronic dialer 44 and microphone amplifier 45. The subscriber hears a signal with a frequency of 425 Hz , which is a standard “station answer” signal in telephony.

If the subscriber does not dial the number within 20 seconds, the DSP processor that processes the frequency signaling from the electronic dialer in the form of dual-frequency DTMF transmissions sends a busy signal. The subscriber must hang up and dial the end code (usually the symbol "*" or "#"). After that, the DSP again sends a 425 Hz signal, constantly feeding the filter capacitor C of the rectifier unit 38.

If the subscriber picks up the phone and hears the signal “station response” dials the number using the electronic dialer 44, the DSP processor (for example, 48) analyzes these signals in digital form and transmits the information to the microcontroller 51 for organization

subsequent call the required subscriber and establish a connection through the digital switch 53.

After talking with another subscriber, the caller hangs up and presses the end button on the electronic dialer. This signal is also analyzed by the DSP for the standard call termination procedure.

Consider the situation of calling the subscriber. If the called subscriber is free, the microcontroller transmits a command to the DSP via the internal bus to send a ring signal to the free subscriber. The call signal differs from the “station answer” signal primarily by a higher level. Secondly, this signal additionally charges the storage capacitor. If the voltage on the resistive rectifier of the rectified voltage exceeds the level of the DC voltage at the output of the DC \ DC converter, the comparator D1 will work in the block 40 of the user terminal and through the contacts K1 of the executive relay K1, the sound transformer ZP 42 will be connected to the input line 35, which will reproduce the input ringing signal. The ringing signal may be simply harmonic or musical sinusoidal. The digital equivalent of this signal is stored in the DSP. A prerequisite for the operation of the calling device is a sufficient signal level at the entrance to the subscriber terminal. As a calling device, a piezoacoustic generator with a high efficiency with low energy consumption is used.

When the called party answers, he picks up the handset and presses the answer button. This signal is analyzed by the DSP and results in the removal of the ringing signal.

An important condition for the operation of the terminal is the use of low-power components of the subscriber terminal, such as an electronic dialer, a microphone amplifier and a ringing device. All these conditions are satisfied by modern commercially available components.

The PBX itself is a single-board electronic device with a control processor, digital switch and signal processors. The control and digital switching board is made on a standard Euro-constructive board with dimensions 230 × 220 × 1.5 mm. The control board contains a RISK microcontroller on an ST-microelectronics ST10F269Z2Q6 chip, a MITEL MT90820AP TDM 16 × 16E1 digital switch, and a clock generator-generator on an MT9042CP chip.

There are two connectors on the board for connecting additional mezzanine cards of linear LIU transceivers of the E1 tract on the REV 2554 microcircuits of the company

SIEMENS and the mezzanine board of signal processors on ADSP-2181 microcircuits of ANALOG DEVICES company (see Photo 3).

There is a board of optical multiplexers installed on the station side directly in the Euro cassette with a digital TDM switch.

The terminal subscriber unit with two Fiber-Chanel transceivers type HGLM-1063 manufactured by HEWLETT PACKARD can be made as a separate unit in the 19 "construct and has dimensions of 480 × 125 × 45 mm.

BIBLIOGRAPHY

Patent documents

1. EP 0829995 A3 LAN telephone system.date of filing 09/16/1997

2. EP 0981227 A3 Power feeding system for telephone terminal in LAN date of filing 08/12/1999

3. EP 0693238 A1 A home and small business phone system for operation on a single internal twisted pair line date of filling 03/31/1994

4. EP 1122904 A2 Access node for optical networks with variable access wavelengths date of filling 01/10/2001

5. EP 1472847 A1 Streaming multimedia data over a network having a variable bandwidth date of filling 01/27/2003

6. EP 1451695 A1 System, method, and data structure for multimedia communications date of filling 02/21/2002

7. EP 1442402 A2 Low cost system method apparatus and way of doing business for the conveyance and electronic labeling and transference of secure multimedia and data products date of filling 01/04/2002

8. EP 1237341 A1 Method and system for initializing VDSL (Very high bit rate Subscriber Line) communications using tone space adjustment date of filling 02/13/2002

9. EP 1347664 A1 Telephone system for wireless LAN with roaming control date of filling 11.28.2002

10. EP 1112646 A1 Voice over internet protocol telephone system and method date of filling 08/12/1999

11. EP 0981227 A2 Power feeding system for telephone terminal in LAN date of filling 08/12/1999

12. EP 0829995 A2 LAN telephone system date of filling 09/16/1997

13. US 6378130 B1, Time Wamer Entertainment Company date of filling 04/23/2002

14. US 6539546 B1, ADS Telecommunications date of filling 03/25/2003

15. US 5,808,767 A, Bell Atlantic Network Services 15, date of filling 1998

16. US 5598541 A, LSI Logic Corporation date of filling 02/28/1997

17. US 6185203 B1, Vixel Corporation date of filling 02/06/2001

18. US 6,597,691 B1, Ancor Communications date of filling 07/22/2003

Non-Patent Documents

ANSI INCITS 230-1994 (R1999) - Fiber Channel - Physical and Signaling Interface (FC - PH)

ANSI INCITS 272-1996 (R2001) - Fiber Channel - Arbitrated Loop (FC - AL)

ANSI INCITS 326-1999 - Fiber Channel - Low Cost 10-km Optical 1063-Mbaud Interface (100-SM-LC-L)

ANSI INCITS 332: 1999 / AM1-2003 - Fiber Channel Arbiturated Loop (FC - AL - 2)

ANSI INCITS 342-2001 - Fiber Channel Backbone (FC - BB)

ANSI INCITS 356-2002 - Fiber Channel - Audio Video (FC - AV)

Hewlett - Packard HGLM - 1063 Fiber Channel gbaud optical link module - Technical Datasheet

Claims (1)

Distributed multiservice telecommunication system consisting of a digital automatic telephone exchange (PBX) connected to a public switched telephone network (PSTN) and to a gateway equipment for accessing PBX subscribers via IP protocol to IP-telephony network, a router with Internet access via a broadband line WAN access, a communication line from the router to the gateway, characterized in that it is equipped with a digital multiplexer unit with optoelectronic transceivers connected to the digital exchange and the router, under connected through individual fiber-optic lines to a fiber-optic communication line (FOCL), made on the basis of a multi-core fiber optic cable with optocross, and terminal subscriber units (VoLAN), each of which is connected to the corresponding core of the fiber-optic cable and connected by Ethernet switches, personal computers and telephone subscriber terminals.