WO2005011244A2

WO2005011244A2 - Method of controlling a service centralizing system in telephone networks, and corresponding system and gateway

Info

Publication number: WO2005011244A2
Application number: PCT/BR2004/000133
Authority: WO
Inventors: Ronaldo Kleber Da Fonseca; Sergio Czajkowski; Norberto Pedro Kleinubing Zakszewski; Silvio Favaro; Athair Athaide Portes; Marcelo Takashi Uemura; Osmar Luis Vioti; Thomaz M. N. Verastegui
Original assignee: Siemens Aktiengesellschaft
Priority date: 2003-07-25
Filing date: 2004-07-26
Publication date: 2005-02-03
Also published as: WO2005011244A3; BR0302529A

Abstract

The present invention relates to a Gateway (100) of Supplementary Services, PABX and Centrex, which makes available supplementary services to subscribers, PABX and Centrex subscribers, in a centralized and uniform way, to any type of subscriber (analog, digital, V5.x, wireless, movable cell telephone or public telephone) belonging to the Commuted Public Telephone System (CPTS), connected to the telephone central of any technology (analog or digital) of any size (large-size, medium-size or small-size). One of the objectives of the present invention is achieved by means of a system of centralizing services to subscribers of various origins in telephone networks, the system being characterized by comprising: a Gateway (100) provided with a central control unit (1); a subscriber service unit (3); a database and data storing unit (5); the central control unit (1) being associated to a telephone network, the telephone network comprising centrals of the public network, the subscriber service unit (3) comprising functions of answering subscribers, stored in the database and data storing unit (5), the Gateway (100) comprising, in the database and data storing unit (5), a virtual calling number of the subscriber, the virtual number of the subscriber corresponding to the subscriber recognition number in the telephone network, the subscriber recognition number being deleted from the local central of the public network associated to the subscriber and transferred to the Gateway (100).

Description

Title: "SERVICE CENTRALIZING SYSTEM IN TELEPHONE NETWORKS, A METHOD OF CONTROLLING A SERVICE CENTRALIZING SYSTEM IN TELEPHONE NETWORKS AND A SERVICE CENTRALIZING SYSTEM GATEWAY IN TELEPHONE NETWORKS" The present invention relates to a Supplementary Services

Gateway that makes available an assembly of facilities offered in a centralized and uniform way to any type of user belonging to the Commuted Public Telephone System (CPTS). The CPTS comprises all types of existing telephone centrals, either fixed or moveable, analog or digital, which form the "public network" of telecommunications, while the user may be any type of subscriber, as for example, analog, digital, Centrex (CENTRal office Exchange service) having the function of a virtual PABX), PABX, xDSL, V5.x, wireless, cellular movable telephone or public telephone connected to the telephone central of any technology (analog or digital) and size (large, me- dium or small). The subscriber belonging to the Commuted Public Telephone System will hereinafter be called merely a subscriber. Description of the Prior Art A Supplementary Service Gateway is constituted by a hardware and software architecture developed to provide additional or supplementary services in addition to those offered by the basic telephony to the network elements that are interconnected to it. It will hereinafter be called simply Gateway. The supplementary services began to be offered to subscribers with the advent of the Stored Program Public Centrals (SPPC). This technol- ogy of centrals enables one to assign to the subscriber's line specific services which he himself will program, activate, use, verify or cancel in a dynamic way. These services are supplied and programmed at the local central, where the subscriber will be directly connected, through a physical line, the database of which is specifically prepared for him. In addition to the supplementary services, the SPPCs offer the

Centrex subscriber services, which enable ordinary subscribers directly con- nected to them to have access to services of the virtual PABX type, without any need to alter their centrals. The Contrex services differ as a function of the various makers of telephone centrals existing in the network. This brings to the subscriber several options of services, but at the same time several compatibility problems, since they are used at a corporative level by companies. Depending upon the physical location where the company is, and to which telephone central it is connected, the Centrex services and even supplementary services will have specific characteristics, which often become incompatible. The incompatibilities arise as a function because the process- ing codes for programming, consultation, use, etc., of the services are not uniformized between manufacturers. Each use s a solution (combination of keys to be used, for example *21# for Call forwarding, *66# for Call completion busy subscriber), etc. According to the present invention, one proposes some ways of uniformizing the services, assuming that the local central is the one that performs part of the functions required for this purpose. Thus, the present invention enables one to uniformize these services so as to make them compatible in any geographic region in which the company is located. Some solutions of the prior art offer systems having a Gateway, and the following documents are cited, for example. Document US 5,539,817 describes a telephone system that integrates Centrex-type lines with the public telephone network. According to this solution, one makes use of an I EC (Inter Exchange Server) type central, which makes the interconnection of the Centex lines with the public tele- phone line. One of the disadvantages of the solution described in this document lies in the fact that the interconnection of telephone centrals is not foreseen. Document US 5,892,821 discloses a Centrex telephone system for a wide covering area, which uses the functionality of the system for a plu- rality of telephone centrals. The system enables a number of Centrex centrals to be interconnected and connected, the interconnection being made through the public telephone network and controlled through a signaling con- trol point (SCP). The solution, however, does not enable one to integrate different types of telephone centrals. Another solution having the same type of operation concept is described in document US 5,247,571. This document discloses a Centrex telephone system for a wide covering area, comprising a plurality of telephone central in different regions. One of the disadvantages of the described system is that the possibility of integrating different telephone centrals is not present. Brief Description and Objectives of the Invention According to the teachings of the present invention, it is possible to interconnect telephone centrals indistinctly of their technology (whether analog, digital, large-size, medium-size or small-size), so that their subscribers will receive, in a centralized way, the facilities of supplementary services available at a SPPC, as for instance, conferences with three or more partici- pants, automatic transfer, waiting call, programmed call desviation, follow- me, controlled call blocking, caller number identification, call capture, automatic recall, etc. Even new services that may be developed in the Gateway may be extended to all their subscribers. In addition to the advantages of uniformizing services and con- centrating these means in the Gateway, it is not necessary that the local central where the subscriber is connected should be prepared for offering them. It is not necessary that attributes of the services provided by the Gateway should be assigned to these subscribers, since they are now recognized as virtual subscribers therein. The expression virtual subscriber is due to the fact that he will be physically connected to the central of origin, but he will be logically represented as a subscriber belonging to the Gateway. In this way, all his attributes necessary for the functioning of facilities will be available at the Gateway. From the point of view of operation and reliability, another great difference of the object of the present invention is the fact that one is concentrating tariffing and programming data of the database of the Gateway. At present, these functions are decentralized and are extremely expensive for the operating companies (administration and operation costs). Functions of the Gateway The main functions that stand out at the Gateway as a telecommunication network element are the following. - programming, activation, utilization, verification or cancellation

(database) of the characteristics of supplementary services of the subscribers (for instance, consultation, transfer, conference, waiting call, identification of the caller number, call capture, automatic recall, etc.). That means that one of the main characteristics of the system is that the subscriber's line at the local central where he is connected does not need to have specific characteristics of supplementary services provided by the Gateway, since this function will be performed at a virtual port, which represents the subscriber; - control and rooting of the originated and terminated calls, taking into account the logic of the services assigned to the subscriber at the Gate- way; - concentration and uniformization of functions and characteristics of the supplementary services to subscribers; - interpretation of the various control signals of establishment, answering, disconnection of a call, signal of resuming the selection tone - hook flash, etc., to enable one to make calls and use of the services; - application of the tones and announcements for establishing calls and performing services; - receiving, storing and analyzing the signals selected by the subscribers for establishing, using and tariffing the subscriber's calls; - control of blocking/releasing the subscribers as a function of the various conditions required, as for example, blocking calls for lack of payment, administrative blocking for maintenance, blocking controlled by the subscriber, among others; - determining characteristics of the virtual subscriber represented at the Gateway as a function of the information received through the signaling of junction with the CPTS or received at the voice channel (for example, the calling subscriber number, subscriber category, origin, etc.), provided by the central to which the subscriber is physically connected. Objectives of the Invention The objectives of the present invention are a Gateway for making available supplementary services to subscribers, in a centralized and uni- fomized way, to any type of subscriber (analog, digital, Centrex (CENTRal office Exchange service) having the function of a virtual PABX), PABX,xDSL, V5.x, wireless, cellular movable telephone or public telephone connected to the telephone central of any technology (analog or digital) and size (large, medium or small) and that avoids the need to provide local telephone cen- trals with additional equipment, which is usually required for centralizing and/or performing services of this nature. One of the objectives of the present invention is achieved by means of a centralized service system in telephone network, which comprises: a central control unit, an access interface, a subscriber's service unit, a database and data storing unit, the central control unit being associated to a telephone network through the access interface, the telephone network comprising public network centrals, the subscriber's service unit comprising functions of answering the subscribers' calls at the database and data storing unit, and database and data storing unit comprising reference-file information associated to the subscriber and data referring to subscriber's calls, tariffing and services. The objectives of the present invention are also achieved by means of a method of controlling a service centralization system in telephone networks, which comprises steps of accessing a local central through a direct line, transferring the subscriber directly to a Gateway; calling a virtual subscriber number or a single service number; canceling the occupation at the Gateway by the signaling, extending the virtual subscriber number to supplementary services available at the Gateway; correlating the virtual subscriber number with the local central, establishing a voice way as far as the central of origin and the subscriber, applying a selection tone to the subscriber after establishing the voice way. Brief Description of the Drawing The present invention will now be described in greater detail with reference to an embodiment represented in the drawings. The figures show: Figure 1 is a schematic diagram of the architecture of hardware and software of the Gateway, indicating its components; Figure 2 is a message-exchange diagram when a subscriber having the "Direct Line" facility originates a call through the Gateway, according to the teachings of the present invention; Figure 3 is a message-exchange diagram when a subscriber who is connected to a local central without the need for a "Direct Line" originates a call through the Gateway, according to the teachings of the present invention; Figure 4 is a message-exchange diagram when a call is finished at a subscriber who is created at the Gateway, according to the teachings of the present invention; and Figure 5 is a network-topology diagram indicating where the Gateway of the present invention is located in the existing telecommunication network.

Detailed Description of the Figures Architecture of hardware and software of the Gateway As can be seen from figure 1 , the architecture of the Gateway 100 of the present invention comprises the following elements; - a Central Coordination / Control unit 1 , which controls the elements, permitting/coordinating all the calls and operations treated by the Gateway 100 - access interface 2 with the centrals of the public network, which will permit access to the services made available; this access interface 2 makes available the signaling required for routing and establishing the calls; any signaling foreseen for junction between telephone centrals of the CPTS network may be connected to this interface; - a subscriber service unit 3 with its respective services; - in the case of a solution integrated in a package network, one should foresee the existence of an interconnection unit 4 with the respective telephone network (for instance, H.323, SIP, ATM, FR, MGCP, Voip, H.248, SIP-T, etc.); - a database and data storing unit 5, at which the characteristics of the virtual subscribers are programmed and the permanent and semipermanent data of the calls, tariffing and services are stored; - central operation unit 6 accounting for operation, administration and maintenance - OAM) of the Gateway; - a matrix of commutation of the voice ways 8; - a "in-band" control recognition unit 7; the term "in-band" means that the signaling (for example, the signal of resuming the selection tone, that is to say, the flash signal used in the supplementary services) is sent within the voice channel, being therefore an audible frequency signal; when someone enters #, *, they will be heard by tow subscribers who are in conversation. From the structure of the Gateway 100, the following steps of a control method are foreseen for organizing the flow of calls to the originated and finished traffic. Virtual Subscribers In order for the centralization system of the present invention to operate, one foresees the creation of a virtual subscriber within the sub- scriber service 3 and the storage of his characteristics in a database 5, so that he can be recognized by the Gateway 100. The creation of the virtual subscriber is necessary because, upon installing the system of the present invention, the subscriber of the local telephone central does not exist any longer for the CPTS network. This virtual subscriber will now represent him from the Gateway 100, for both originated and finished traffic. From this moment on, the telephone network will view this subscriber in question only through the Gateway 100. The subscriber of the local central still needs to have a telephone number assigned to him, but the latter is only used for the direct routing between the Gateway 100 and its central. In the case of finished traffic for this subscriber in question, the valid number for the CPTS network is the virtual subscriber's number, which is created at the Gateway 100. In this way, all the calls will be directed to the Gateway 100, which will route them to any local central to which he is physically connected. The number of this terminal at the local telephone central may be a fictitious number that is only known by it and by the Gateway 100. The identification of the virtual subscriber in an originated traffic is made from the number of the calling subscriber, received, for instance, through the IAM (Initial Address Message). The IAM applicable when using the ISUP signaling. In another type of signaling link, one might use another message. The important thing is to observe that the IAM message of the ISUP protocol in this case should be interpreted as the "A number" information of the subscriber of the local central. In some situations, the IAM does not bring the A number, and later this number is requested from the central of origin. In the case of other signalings (for example MFC R2) the citation of the A number information is not made via IAM (specific of the ISUP), but rather by another method defined by the national standard. Method of routing to the Gateway 100 for originated traffic: Thus, in order for the subscriber to reach the Gateway 100 and make ordinary telephone calls, PABX or Centrex having telephone services, the Gateway 100 should be provided in such a way, as exemplified in figures 2, 3 and 4, which will be presented in items C, D and E. On considers, for instance, that the calling subscriber and the called subscriber are analog and the routing is through, for instance, the ISUP signaling among centrals and Gateway 100. In the solution of the Gateway 100, any other signaling may equally be utilized. For a better understanding of the method, one may consider an example of a connection established between the subscriber who is using the system of the present invention and an ordinary subscriber of the CPTS network, and another example between two subscribers using the system of the present invention. A) Connection between subscriber of the system of the present invention (user "X") and an ordinary subscriber of the CPTS network ("Y" user) When the subscriber X initiates a call to the subscriber Y, the way of signalizing this intention to the Gateway 100 may be either automatic or by selecting a pre-defined code, depending upon the resources of the local central of the CPTS network. From this point onwards, everything will happen as if the call were being originated from the virtual subscriber of the Gateway 100. In the opposite way, when the subscriber Y makes a call to the subscriber X, the telephone central of Y will no longer seek the telephone central of X, since in this case the number of the user X will be found at the Gateway 100, and no longer at the telephone central of X. The telephone central of X may remain without any alteration in its configuration. The connection from the user Y will be established with the user X through the Gateway 100.

B) Connection between two subscribers using the system of the present invention (user "X" and user "Z") In this situation, there will be a conjunction of the two situations created in item A, so that, when the user X picks ups the phone, his connection with the telephone central X will be diverted to the Gateway 100, and the latter, in turn, will establish the connection with the subscriber Z through the telephone central Z, directly through this Gateway 100 or even through an- other Gateway 100 that serves the subscriber Z. Thus, the telephone centrals do not need to be altered, and the system of the present invention may even be configured through a plurality of Gateways, if necessary. In order for one to understand the above-described method, two embodiments of the system will now be described with reference to the figures.

C) Access through the "Direct Line" facility Figure 2 illustrates the flow of call described hereinafter. The subscriber A1 (indication 2.1 ) sends a busy signal to the local central (indica- tion 2.2), which has the "direct line" facility programmed for it. At the local central, the service "direct line" is programmed so as to reach the Gateway 100 (indication 2.3) calling a virtual number of the sub- scriber or a single service number existing therein. In the case of the single service number, the Gateway 100 selects the virtual number based on the number/category of the calling subscriber, consulting database unit 5 of the Gateway 100. This number of the virtual subscriber serves to represent the subscriber A2 at the Gateway 100. Upon effecting occupation of the Gateway 100 by means of the ISUP signaling (as an example), the number of the virtual subscriber immediately extends all the supplementary services assigned to him to the subscriber who is connected at the central of origin (indication 2.2). The call number of the subscriber A2 is transported by the signaling in the telecommunication network and is stored and correlated at the database 5 of the Gateway 100 with the number of the virtual subscriber that represents him. This number of virtual subscriber created at the Gateway 100 has all the programmings of supplementary services provided by the Gate- way 100 to the subscribers represented by it, as well as tariffing, blockings, etc, as every SPPC can provide. Once this call reaches the Gateway 100, right after the signaling (indication 2.4) usually necessary to the telecommunication network, the voice way (indication 2.5) is established between the central or of origin (indi- cation 2.2) and the subscriber A2. Right afterwards, the Gateway 100 applied the selection tone (indication 2.6) to the subscriber A2. This subscriber, in turn, makes the dialing selection (indication 2.7) of the number of the subscriber B2 to be called through the voice way previously established (indication 2.5). These figures reach the Gateway 100, which address resolution (indication 2.8) and initiates the process of interconnection with the destination central (indication 2.10) after the signaling exchange (indication 2.9). When the signaling exchange has been completed, the destination central (indication 1.10) applies the call control tone (indication 2.11) to the subscriber A2 of origin (indication 2.1), as well as the call current (indica- tion 2.12) to the subscriber B2 (indication 2.13), following the normal processing of a telephone call. When the subscriber B2 (indication 2.13) answers the call, the answering information (indication 2.14) reaches the Gateway (indication 2.3), which may finally establish the voice way between origin and destination (indication (2.15). From the interconnection with the Gateway 100, the subscriber A2 connected to the local central (indication 2.2) may request the supplementary services for the virtual subscribers available at the Gateway 100, as if they were available at the local central (of origin) (indication 2.2). Also, the procedures of call tariffing and supervising by the Gateway 100 are initiated. D) Routing by using the resources of category, caller number and/or intercep- tjon In the cases where the direct-line facility is not available at the local central, this function is assumed by the Gateway 100. The first dialing figures are routed to the Gateway 100 by using a single service code. The term dialing figures refers to the pre-programming made at the subscriber, so that he will have access to the Gateway 100, the identification of this preprogramming being made by the telephone central. From the number of the calling subscriber (number of subscriber of the local central), the Gateway 100 make the search for the virtual subscriber at its database and correlates it and establishes a correlation between them, in order to provide a direct association between them. Figure 3 illustrates a basic call of this scenery. The subscriber A3 (indication 3.1 ) accesses the local central (CPTS) (indication 3.2), and the latter, in its normal processing, sends the selection tone (indication 3.4). The subscriber A3 selects the dialing figures or code of access to the service (in- dication 3.5), which is collected by the local central. From these collected figures, the local central establishes a connection with the Gateway 100 (indication 3.3) by using the signaling (indication 3.6) ISUP. The local central (indication 3.2) may put guide figures before the figures (indication 3.5) selected by the subscriber A3 (indication 3.1 ), before routing the call to the Ga- teway 100 (indication 3.3). The guide figures may be used, so that the call may be routed by the CPTS so as to reach the Gateway. The Gateway 100 uses the number of the calling subscriber for selecting which number of virtual subscriber should be reached. This number of virtual subscriber serves to represent the subscriber A3 at the Gateway 100. Upon effecting the occupation at the Gateway 100, the number of virtual subscriber immediately extends the supplementary services assigned to him to the subscriber A3, who is connected at the central of origin, or at the local one. The calling number of the subscriber A3 to the telecommunication network is created at the Gateway 100 and correlated to the local cen- tral. This number of virtual subscriber created at the Gateway 100 has all the programmings of supplementary services provided to the subscriber represented by it, as well as tariffing, blockings, etc., as any SPPC can provide. Once this call has reached the Gateway 100, right after the signaling exchange (indication 3.6) usually necessary for the telecommunication network, the voice way (indication 3.7) is established as far as the central of origin (indication 3.2) and the subscriber A3. Depending upon the figures received by the Gateway 100, it applies a selection tone (indication 3.8) indicating to the subscriber A3 the need to send more figures (indication 3.9) to complete the dialing. From this point on, the procedure is analogous to that of the preceding item, the indications being made with a corresponding index (3.x). E) "Direct Line" facility existing on the telephone apparatus of the user In the cases in which the local central does not have resources as described in the preceding items A) and B), one used the direct-line facility existing on the telephone set of the user. This type of telephone should automatically send the figures with the access number to reach the Gateway

100. This should always happen when the user initiates a call. In this case, the access code of the Gateway 100 will be preprogrammed at the telephone of the user, whereas in item A), represented by figure 2, the programming is carried out directly at the local central. The access code may be single for the whole Gateway 100 or individualized by a terminal using it. In the case of a single access code, the association of the number of the local subscriber and the virtual number will be effected through information previously available at the database of the Gateway 100. From this point on, the procedure is analogous to that described before in item A).

Method of routing to the Gateway 100 for finished traffic In this scenery, any subscriber belonging to the CPTS will call a subscriber who is represented at the Gateway 100. The subscriber of the CPTS selects the virtual number of the subscriber belonging to the Gateway 100, which is known and disclosed according to the national/international numbering plan. Figure 4 lustrates the flow of call described hereinafter. The subscriber A4 (indication 4.1 ) accesses the local central (CPTS) (indication 4.2) and selects the number of the subscriber B4 (indication 4.13), who, in turn, is created at the database of the Gateway 100 (indication 4.3). The Gateway 100 is reached through the signaling exchange ISUP (indication 4.4) by the conventional method of the CPTS and makes the search for the number of the virtual subscriber associated to the subscriber B4, who is physically connected to a local central (indication 4.8). The Gateway 100 makes the ad- dress resolution (indication 4.6) and through the signaling exchange (indication 4.7) the call will be routed to the local central of the subscriber B4. The call reaches the local central of destination, which applies a call control tone (indication 4.9) to the calling subscriber A4. At the same time it applies a call current (indication 4.10) to the called subscriber B4. After answering (indica- tion 4.11) the local central of destination passes this information (indication 4.12) to the Gateway 100, which finally establishes the voice ways between origin and destination (indication 4.14). The virtual subscriber immediately extends all the supplementary services assigned to him to the subscriber B4, who is connected at the local central of destination. Topology of physical implementation of the Gateway Figure 5 presents one of the possible topologies for interconnecting the Gateway 100 with the elements of a telecommunication network. The subscribers (indication 5.1 ) (analog, digital, V.δ.x, xDSL, Wireless, movable cell telephone (movable network) and public telephone are connected to a local central (indication 5.2), which may be directed connected to the Gateway 100 (indication 5.4) or connected through a higher- hierarchy central of the public network (CPTS Gateway 5.3) or to the movable PLMN network (indication 5.5). The traffic will be originated and finished at theses subscribers (indication 5.1 ), the control over the call being effected at the Gateway 100 (indication 5.4). Essentially, the Gateway 100 supplies supplementary services provided to the subscribers by it, represented in a centralized and uniform way, independent of the access technology to which the subscriber is connected. In the event of making use of more than one Gateway 100, these multiple Gateways will make the interconnection between themselves through the public telephone network. So, it will not be necessary to install any additional cabling, which brings an advantage of costs and implementation to the system of the present invention. Signal of resuming dialing tone (hook flash signal) at the Gateway 100 In the case of using supplementary services, these are generally carried out when the subscriber is in the state of conversation. In this case, the subscriber needs to signal to the Gateway 100 the intention of using a service. This takes place when he carries out special actions on the telephone set (for instance, pressing the "flash" key, dialing some special figure or combination of keys). This action is known as a signal of resuming the selection tone. One uses the DTMF signal(s) with DTMF # sequence (hash- value 12) and * (asterisk value 11 ) as a signal of resuming the selection tone (hook flash), which is necessary for carrying out the various supplementary services provided by the Gateway 100. However, one may use other combinations of DTMF signal(s), the sequence or figures of which will be used as a signal of resuming selection tone ("hook flash" signal). Also, one may use AC frequency signals overlapped to the DC signal of the line, depending upon the form of wave, frequency, modulation and amplitude of the signals generated by the subscriber at the central or origin, according to the resources available by the latter, in order to make use of the Gateway 100 as a signal of resuming the selection tone (hook flash signal). Among the advantages of the system and method of the present invention, one may cite that the Gateway 100 permits, in a centralized way, the utilization of a solution applied to subscribers independently of the tech- nology of the central to which the latter are connected, and further in a way independent of the nature of the terminals, or even access from a public telephone. In addition, the Gateway 100 of the present invention permits, in a centralized way, the control over tariffing of the subscriber who is at the local central, as well as the programming, activation, utilization, verification and cancellation of supplementary services to the subscriber, PABX and Centrex subscriber, who is at the local central. A preferred embodiment having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents. Glossary:

ATM - Asynchronous Transfer Mode SPPC - Stored-program Public Centrals DSL - Digital Subscriber Line

DTMF - Dual Tone Multi-Frequency FR - Frame Relay IAM - Initial Address Message ISUP - ISDN User Part ISDN - Integrated Services Digital Network MGCP - Media Gateway Control Protocol SIP - Session Initiation Protocol CPTS - Commuted Public Telephone System

V5.x - Interface V5.x

VoIP - Voice over Internet Protocol

Claims

1. A system of centralizing services for subscribers of various origins in telephone networks, the system being characterized by comprising: - a Gateway (100) provided with a central control unit (1); - a subscriber service unit (3); - a database and data storing unit (5); the central control unit (1) being associated to a telephone network, the telephone network comprising centrals of the public network, the subscriber service unit (3) comprising functions of answering subscribers, stored in the database and data storing unit (5), the Gateway (100) comprising, in the database and data storing unit (5), a virtual calling number of the subscriber, the virtual number of the subscriber corresponding to the subscriber recognition number in the telephone network, the subscriber recognition number being deleted from the local central of the public network associated to the subscriber and transferred to the Gateway (100).

2. A system according to claim 1 , characterized in that the central of the public network associated to the subscriber is pre-programmed for the originated traffic calls to be routed from the local central of the public network to the Gateway (100).

3. A system according to claim 1 , characterized in that the recognition of the virtual subscriber in originated traffic is made by receiving the signaling from the subscriber connected to the central of the public network.

4. A system according to claim 1 , 2, or 3, characterized in that the database and data storing unit (5) comprises reference-file information associated to the subscriber and data referring to calls, tariffing and services to the subscriber.

5. A system according to claim 4, characterized by comprising an interconnection unit (4), the interconnection unit (4) interconnecting the cen- tral control unit (1 ) with various types of telephone network.

6. A system according to claim 5, characterized in that the central control unit (1) comprises a voice-way commuting matrix (8), associated to the public-network access unit (2).

7. A system according to claim 6, characterized in that the central control unit (1 ) comprises a recognizing unit (7) for recognizing "in-band" control signals.

8. A system according to claim 7, characterized by comprising a central operation unit (6), the central operation unit (6) controlling the operation, administration and maintenance of the system.

9. System according to claim 7, characterized in that the communication between the subscriber and the central control unit (1) is made through DTMF signal(s).

10. A system according to claim 9, characterized in that the resuming of the selection tone is made by AC frequency overlapped to the DC signal of the line.

11. A system according to claim 7, characterized in that the re- suming of the selection tone is made by modulation at frequency.

12. A system according to claim 7, characterized in that the resuming of the selection tone is made by modulation at amplitude.

13. A system according to claim 7, characterized in that the central control unit (1) comprises a subscriber tariffing control in a centralized way.

14. A system according to claim 13, characterized in that the central operation unit (6) enables one to program, activate, utilize, verify and cancel supplementary services to subscribers.

15. A method of controlling a system of centralizing services in telephone networks, characterized by comprising the steps of: - accessing the local central; -recognizing the number of the calling subscriber at the telephone central and transferring the subscriber directly to a Gateway (100) when this subscriber has a virtual subscriber number at the Gateway (100); - effecting the occupation at the Gateway (100) by signaling; - extending the virtual subscriber number to supplementary services available at the Gateway (100); - correlating the virtual subscriber number with the local central; - establishing a voice way as far as the central of origin and the subscriber; - canceling the occupation at the Gateway (100) by signaling.

16. A method according to claim 15, characterized in that it further comprises the step of: - applying a selection tone to the subscriber after establishing the voice way.

17. A method according to claim 16, characterized by comprising the steps of: - carrying out the interconnection with the central of destination after an exchange of signaling; - applying a call tone control to the subscriber of origin, as well as a call current to the other subscriber.

18. A method of controlling a system of centralizing services in the telephone network, characterized by comprising the steps of: - accessing a local central; - recognizing the number of the called subscriber in the telephone network and transferring the calling subscriber directly to the Gateway (100); - effecting the occupation at the Gateway (100) by signaling; - establishing a voice way as far as a central of origin and the subscriber; - canceling the occupation at the Gateway (100) by signaling.

19. A method according to claim 18, characterized in that, in the step of establishing the voice way, the traffic carried out through the central of the subscriber called from the Gateway (100).