WO2005011253A1

WO2005011253A1 - Centralized telephone control and blockage system, gateway and method of controlling and blocking telephones

Info

Publication number: WO2005011253A1
Application number: PCT/BR2004/000130
Authority: WO
Inventors: Ronaldo Kleber Da Fonseca; Mario Yamazaki; Sergio Czajkowski; Norberto Pedro Kleinubing Zakszewski
Original assignee: Siemens Aktiengesellschaft
Priority date: 2003-07-25
Filing date: 2004-07-23
Publication date: 2005-02-03
Also published as: BR0302530A

Abstract

A centralized telephone control and blockage system which implements an anti-tampering system (anti-fraud blockage system) for Public Use Telephones (PUT) is described. The system comprises (i) an exchange of origin (20) to which multiple telephones are associated (10); (ii) an exchange of destination (11) to which multiple telephones are associated; and (iii) at least one gateway (30) associated to the exchange of origin (20) and/or to the exchange of destination (11); the gateway (30) receiving and allocating calls coming from the exchange of origin (20), the calls allocated having anti-tampering devices, the gateway (30) associating origin to destination through a voice path (16). A gateway (30) especially used in a telephone control and blockage system is also described, as well as a method of controlling and blocking telephones which may be used in the system and gateway according to the invention.

Description

"CENTRALIZED TELEPHONE CONTROL AND BLOCKAGE SYSTEM, GATEWAY AND METHOD FOR CONTROLLING AND BLOCKING TELEPHONES " The present invention relates to a centralized telephone control and blockage system which implements an anti-tampering system (anti-fraud blockage system) for public use telephones (TUP) , in addition to a gateway used in the system and a method for controlling and blocking telephones . Description of the State of the Art Tampering with public telephones (PTs) , as well as vandalism, has always caused countless losses to telephone operators which, on account of this, seek methods to curtail the loss of income . Many improvements have been incorporated to PTs to avoid such problems, but comparatively few improvements have been made to telephone exchanges . The large majority of telephone operators use anti-tampering PT which was developed for such purpose, and the aim is to avoid frequency signals at the beginning of the call (referred to as "PT signature"), and also during the call. These signals are received by an anti-tampering device / interface (whose HW is part of the solution) installed on the subscriber's line (wires A and B) in connection with the telephone exchange's GD (General Distributor) . Said signals arrive at the exchange's GD in a certain "signal / time interval" order, depending on whether the call is local or long-distance. This solution causes various inconveniences to the operators since it is difficult to implement in mechanical and electrical terms because the GD of public exchanges was not designed to have equipment of this kind connected to its original hardware. For each public telephone having the anti-tampering function, hardware is needed to analyze the anti-tampering signals from the PT, installed in the local exchange ' s GD. The maintenance costs of this hardware are rather high and often unfeasible. Added to this is the fact that the possibility of tampering is not eliminated, since access to this type of device is facilitated because the exchange's GD is one of the parts that is most handled and any kind of maintenance on the GD may disconnect this device. Objective of the invention The objective of the present invention is to substitute the current solution (characterized by a solution having individualized treatment) for a solution dealt with in centralized form, thus eliminating the need for an anti- tampering device or interface that is dedicated to a public telephone line. Another objective of this invention is to enable the telephone exchanges, regardless of the technology in use (analogical or digital, large, medium or small-sized) , to offer the anti-tampering function for public telephones in centralized form on the anti-tampering platform, henceforth referred to as Gateway. A further objective of this invention is to enable a multi-vendor solution, namely exchanges where the PT is connected do not require the anti-tampering function that will be provided on the Gateway. The main advantages include the low operating cost and centralized management of O&AM, low maintenance cost and fast programming / installation of this service for telephone lines. In the case of an integrated solution Gateway function implemented within the local exchange, restricted to same-technology equipment) it is not necessary to interconnect the local exchange with another network element, thus eliminating long-distance trunking between the local exchange and the Gateway. Summary of the Invention According to the invention, the objectives set forth above are achieved by a centralized telephone control and blockage system, comprising: (i) an exchange of origin to which multiple telephones are associated; (ii) an exchange of destination to which multiple telephones are associated; and (iii) at least one gateway associated to the exchange of origin and/or to the exchange of destination, the gateway receiving and allocating calls coming from the exchange of origin, the allocated calls having anti- tampering devices, the gateway associating origin to destination by way of a voice path. Conveniently, the gateway can also receive and allocate calls directed to the exchange of destination. According to the invention, the system implements the anti-tampering of public telephones connected to the local or public exchange of the telecommunications network using any technology (analogical or digital) and of any size (large, medium or small) in concentrated fashion on an anti- tampering platform, the so-called Gateway. The objectives set forth above are also achieved, according to the present invention, by a gateway used especially in a centralized telephone control and blockage system, comprising (i) a central coordinating and control unit associated to a billing control unit and an exchange signaling interface with the public network in order to control calls and operations; and (ii) an anti-tampering signals recognition and analysis unit in the billing control unit, an anti-tampering signals recognition and analysis unit capable of receiving and analyzing anti-tampering signals coming from telephones. Additionally, the Gateway platform - anti- tampering platform - according to the invention may also be integrated to the local exchanges. In this case, a large part of the HW (Hardware) already existing at the local exchange is also used for the anti-fraud blockage system. This situation occurs when the local exchange is sufficiently flexible to add new functions and has technology that is compatible with that used in the Gateway. In practice, this generally occurs when the local exchange is manufactured by the same company as the PT Gateway. According to the invention, the gateway can exchange signaling with telecommunications networks by means of a signaling exchange unit with the public network. In this case, the control and billing unit can conveniently provide connection and disconnection of calls based on analyses of the user's actions. Additionally, this billing control unit can also receive the result of anti- tampering signals analysis from the anti-tampering signals recognition and analysis unit. The objectives set forth above are also achieved by this present invention by means of a method for controlling and blocking telephones, comprising the following steps: (a) access from a telephone to an exchange of origin; (b) connection of the exchange of origin with a gateway, which, in the case of integration solution at the local exchange or exchange of origin, is dispensed with; (c) gateway interconnection with the exchange of destination; (d) association of the exchange of destination to a subscriber. Conveniently, the method according to the present invention foresees that in step (b) the connection from the exchange of origin with the gateway is by "direct line" programming. Additionally in step (b) , the gateway can exchange signaling with the exchange of origin and internally allocate a user door containing an activated anti-tampering service. Furthermore, still in step (b) , the gateway can receive signature signals and anti-tampering signals, and after step (b) , the gateway can conveniently establish a voice path with the exchange of origin and apply a selection tone to the telephone. Also, after step (b) and prior to step (c) , the telephone may carry out a dialing selection, whereas in step (c) there may be an exchange of signaling between the gateway and the exchange of destination. Once the signaling exchange is finalized, the exchange of destination preferably applies a call control tone to the subscriber. Further, prior to step (d) there may be a step of sending answering information to the gateway and the establishment of a voice path between origin and destination. Preferably, after step (d) the billing may be sent to the exchange of origin through the gateway. According to the method in the present invention, and, after step (d) , subscriber B being a PUT equipped with anti-tampering mechanism, there are three possible anti- tampering mechanisms: (1) soon after answering the call, the local exchange of destination can send the signature received from the PUT to the gateway; (2) once the call has been established, the local exchange of destination sends the signature received from the PUT to the gateway, and (3) the gateway (control and billing unit) can provide connection and disconnection of calls based on analyses of the signature from the PUT/anti-tampering signals . Brief description of drawings The present invention is described ahead in greater detail, based on an example of execution represented in the drawings. The figures show: Figure 1 - a block diagram of the hardware and software architectural of the gateway that is the object of the present invention; Figure 2 - is a block diagram of message exchange when a PT, having the programmed anti-tampering function, originates a call through the gateway; Figure 3 - is a diagram of message exchange when a call is terminated in a subscriber that is created on the gateway; and Figure 4 - is a diagram of the network topology indicating where the new gateway is located in the already existing telecommunications network. Detailed description of the figures According to a preferred embodiment, and as can be seen from figure 1, the centralized telephone control and blockage system comprises a central coordinating and control unit 1, an exchange signaling interface with the public network 2 , a control and billing unit of PT 3 , an interconnection mechanism (i.e. packages network, open or owner protocol) 4, an anti-tampering signals recognition and analysis unit of PT 7, a database and storage unit 5, an operation, administration and maintenance unit (OAM) 6, and a switching matrix of voice paths 8. Methods of sending to Gateway and call flow to originated traffic: The central coordinating and control unit 1 controls all the elements, enabling and coordinating all calls and operations handled by the Gateway. The signaling exchange interface with the public network 2 enables access or signaling exchange between the existing telecommunications network and the Gateway. This interface provides the signals necessary for sending and establishing ISUP, MFC, and R2D calls, for example. The control and billing unit of PT 3 connects and disconnects the call based on the analysis of the PT user's actions, such as perceiving the withdrawal of the monophone from the PT, PT user dialing, PT disconnection, etc. The result supplied by the anti-tampering signals recognition and analysis unit of PT 7 is analyzed by this unit that decides whether the call may continue or should be disconnected. It also analyzes and applies PT billing. The anti-tampering signals recognition and analysis unit of PT 7 receives and analyzes anti-tampering signals sent by the PT and distinguishes them from the DTMF PT user's signal dialing. The analysis is informed to the control and billing unit of PT 3. In the case of a packages network solution, there is an interconnection unit with the respective network 4 (example H.323, SIP, ATM, FR, MGCP, VOIP, H.248, SIP-T, etc) . The use of a packages network is a special feature of the solution, and may be dispensed with. In the database and storage unit 5, the PTs characteristics are programmed and the permanent and semipermanent data of the calls, billing, etc. are stored. According to figure 2, trunking is considered to be via ISUP signaling between PT exchange origin, PT Gateway and exchange destination of subscriber B. In the example in figure 2 , the PT exchange of origin is a local exchange. In any case, in the Gateway solution, any other signaling between exchanges can equally be used. The PT user 10 accesses the local exchange 20 which has a "direct line" facility programmed for same. In the local exchange 20, the "direct line" service is programmed so as to reach the Gateway 30. Upon detecting the busy signal through the ISUP signaling exchange, for example, the Gateway 30 internally allocates a PT user door with an activated anti-tampering service. This PT user door 10 is to represent user in the Gateway 30 and analyzes the anti-tampering signals of same. From this point onwards, the Gateway activates the PT's internal anti-tampering signals recognition and analysis unit to receive signature signals at the start of the call 70 and other anti-tampering signals sent during the call. At the start of the call, the PT can send these signature signals at the same time that the PT user receives the selection tone from the Gateway. Should the Gateway 30 detect any inconsistency in the signals sent by the PT 10, the call will be disconnected. Otherwise, the call will be continued. Next, after the call has reached the Gateway 30, as soon as the signaling exchange has been finalized 40 as normally necessary for the telecommunications network, the voice path 50 is established to the exchange of origin 20 and the PT user 10. Soon after, the Gateway 30 applies the selection tone 60 to the PT user 10. The PT user 10 makes the dialing selection 80 of B number to be called via the previously established voice path 50. These numbers reach the Gateway 30, which clears the address 90 and starts the interconnection process with the exchange of destination 11 after the signaling exchange 100. Once the signaling exchange is concluded, the exchange of destination 11 applies the call control tone 12 to subscriber A of origin 10, as well as a call current 130 to subscriber B 15 following the normal processing of a telephone call . When subscriber B 15 answers the call, the answer information 150 reaches Gateway 30, which can finally establish the voice path between origin and destination 16. As of interconnection with the Gateway, the PT user 10 connected with the local exchange 20 talks normally with subscriber B. The billing signal 17 will be sent by Gateway 30 to the exchange of origin 20 which in turn will forward it 18 to the PT user 10 in order to decrease the credits of the telephone card or public telephone token. The process of analyzing anti-tampering signals remains activated until the PT user's call is disconnected 10. Method of sending to Gateway for terminated traffic: The call flow for terminated traffic is handled normally in the gateway for the telecommunications network. The difference in relation to originated traffic described in the previous item lies in the fact that the analysis of anti-tampering signals occurs soon after the subscriber answers the call B, at which point the telephone sends it to the Gateway 30. For example, a common subscriber 15 connected to a local exchange or exchange of origin 11 in the network links up to a PT 10 at any exchange of destination 20. Figure 3 illustrates the call flow described as follows. The subscriber 15 accesses the local exchange 11 and selects the subscriber number B, which is a PT 10. After the initial reception of the selected digits, the local exchange 11 forwards the call for the network to exchange ISUP signaling 40, for example, and then is sent to the exchange of destination 20 where it is connected to the former, in this case, a PT 10. The exchange of destination 20 applies the call current to the PT 130 as well as the call control tone 12 to subscriber A 15. After answering 150, the exchange of destination 20 passes this information 150 to Gateway 30 which finally establishes the voice paths between origin and destination 16. The Gateway 30 begins analyzing the anti-tampering signature signals 70 sent by the PT 10 at the start of the call, as well as other anti-tampering signals which are supplied during the course of the call . Should the Gateway 30 detect any inconsistency in the signals sent by the PT 10, the call will be disconnected. Otherwise, the call will be continued. Physical implementation topology of the Gateway: Figure 4 presents a possible topology for implementation of the Gateway in the telecommunications network. The PTs 101 are connected to a local exchange 200 which may be directly connected to the Gateway 400 or connected through a superior hierarchy exchange of the public network (SPTC Gateway) 300. The traffic will be originated and terminated in these PTs 101, and the call control will be carried out through the Gateway 400. Gateway functions : The main functions of the Gateway, illustrated in figure 1, are as follows: - Analysis of the frequency signals codified at the start of the telephone call (signature) and during the course of the call . Should the sequence of these frequencies be validated by the Gateway platform, the call will be permitted (or continued) ; otherwise, it will be disconnected. This analysis is performed by the PT both on originated and terminated traffic. - Control and forwarding of calls originated and terminated from PTs taking into account the application of the anti-tampering function. - Interpretation of the various control signals of the telecommunications network with regards establishing, answering, disconnecting a call, etc., to permit a call to be made . - Receive, analyze and process the anti-tampering signals of the PT, as well as selecting the subscriber to establish a call. - Control of blockage / release by PT based on an analysis of anti-tampering signals and/or required conditions, such as blockage of a PT terminal for administrative or maintenance purposes. - Analysis, control and application of PT billing based on its origin in order to tariff it as previously programmed according to the billing criteria / methods applied as per telecommunications norms . - Creation of a virtual number for forwarding to a

Gateway based on the PT origin from which it is possible to distinguish the distinct billing areas / zones. - Concentration of analysis / implementation of anti-tampering functions at the local exchange, should the Gateway be directly connected thereto or in the Gateway form when the Gateway is not directly connected at the local exchange where the PT is located. Application of tones and announcements to establish / disconnect the call . Public telephones comprising an "anti-tampering" control function send codified frequency signals at the start of the telephone call and during the course of the call. This digits form an electronic key or signature which should be identified or validated by the hardware and software existing on the control platform known as the Gateway. Should the sequence of these frequencies be validated by the Gateway platform, the call will be permitted or continued, otherwise the call will be disconnected. In the Gateway solution, it is not necessary for hardware on the GD that performs the anti-tampering function because this is carried out by the software/hardware on the public exchange SPE (stored program exchange) with the Gateway function. Accordingly, it is suffice that the PT access the

Gateway in order to make the telephone call and the anti- tampering function will be applied during this call . The Gateway can be set up so that it answers the anti-tampering PTs of innumerous SPTC exchanges that are installed in different geographic regions in the country. This solution is to carry out the anti-tampering function in calls originated or terminated from the PT. The present invention concentrates the billing in the Gateway that controls and sends to the exchange of origin to which the subscriber or PT user is connected, when necessary. This difference allows great agility in the control and modification of tariffs, making operating costs especially economical as well as the management functions of these tariffs for the operators where these activities may be concentrated, ensuring streamlined functioning and improved operational performance. Glossary ACM Address Complete Message ANM Answer Message ATM Asynchronous Transfer Mode SPE Stored Program Public Exchanges GD General Distributor DSL Digital Subscriber Line DTMF Dual Tone Multi-Frequency GW Gateway HW Hardware IAM Initial Address Message ISUP ISDN User Part MFC Multi Frequency Code MGCP Media Gateway Control Protocol R2D Signaling R2 Digital SIP Session Initiation

Protocol SPTC Switched Public Telephone System PUT Public Use Telephone PT Public Telephone V5.x Interface V5.x VoIP Voice over Internet Protocol Having described an example of preferable embodiment, it must be emphasized that the scope of the present invention covers other possible variations, and is limited only to the content of the claims attached, including possible equivalents.

Claims

CLAIMS 1. Centralized telephone control and blockage system, characterized by the fact that it comprises: (i) an exchange of origin (20) to which multiple telephones are associated (10); (ii) an exchange of destination (11) to which multiple telephones are associated; and (iii) at least one gateway (30) associated to the exchange of origin (20) and/or exchange of destination (11) , the gateway (30) receiving and allocating the calls coming from the exchange of origin (20), the calls allocated having anti-tampering devices, the gateway (30) associating origin to destination by means of a voice path (16) . 2. System, as claimed in claim 1, characterized by the fact that the gateway (30) also receives and allocates calls directed to the exchange of destination. 3. Gateway (30) especially used in a centralized telephone control and blockage system, characterized by the fact that it comprises : (i) a central coordinating and control unit (1) associated to a billing control unit (3) and an exchange signaling interface with the public network (2) so as to control calls and operations; and (ii) an anti-tampering signals recognition and analysis unit (7) in the billing control unit (3), the anti-tampering signals recognition and analysis unit (7) being able to receive and analyze anti- tampering signals coming from telephones. 4. Gateway, as claimed in claim 3, characterized by the fact that exchange signaling with telecommunications networks by way of the signaling exchange unit with the public network (2). 5. Gateway, as claimed in claim 3, characterized by the fact that the control and billing unit (3) provides call connection and disconnection by analyzing the user's actions . 6. Gateway, as claimed in claim 5, characterized by the fact that the control and billing unit (3) receives the result of anti-tampering signal analysis from the anti- tampering signals recognition and analysis unit (7) . 7. Method for controlling and blocking telephones, characterized by the fact that it comprises the following steps : (a) access from a telephone (10) to an exchange of origin (20) ; (b) connection from the exchange of origin (20) to a gateway (30) , that, in the case of an integrated solution at the local exchange is dispensed with; (c) gateway interconnection (30) with the exchange of destination (11) ; (d) association of the exchange of destination (11) to a subscriber (15) . 8. Method, as claimed in claim 7, characterized by the fact that in step (b) the connection from the exchange of origin (20) to the gateway (30) is by means of a "direct line" program. 9. Method, as claimed in claim 8, characterized by the fact that still in step (b) the gateway (30) exchanges signaling with the exchange of origin (20) and internally allocates a user door containing an activated anti-tampering service. 10. Method, as claimed in claim 9, characterized by the fact that during step (b) the gateway (30) receives signature signals and anti-tampering signals. 11. Method, as claimed in claim 7, characterized by the fact that after step (b) the gateway (30) establishes um voice path with the exchange of origin (50) and applies a selection tone (60) to the telephone (10). 12. Method, as claimed in claim 11, characterized by the fact that after step (b) and prior to step (c) there is a dialing selection (80) by the telephone (10) . 13. Method, as claimed in claim 7, characterized by the fact that in step (c) there is a signaling exchange (100) between the gateway (30) and the exchange of destination (11) . 14. Method, as claimed in claim 13, characterized by the fact that, once the signaling exchange is finalized

(100), the exchange of destination (11) applies a call control tone (12) to the subscriber (15). 15. Method, as claimed in claim 7, characterized by the fact that prior to step (d) there is a step of sending answering information (150) to the gateway (30) and the establishment of a voice path between origin and destination (16) . 16. Method, as claimed in claim 7, characterized by the fact that after step (d) the billing information is sent (17) to the exchange of origin (20) through the gateway (30) . 17. Method, as claimed in claim 7, characterized by the fact that after step (d) , subscriber B being a PUT with an anti-tampering mechanism, soon after the call is answered, the local exchange of destination sends the signature received from the PUT to the gateway. 18. Method, as claimed in claim 7, characterized by the fact that after step (d) , subscriber B being a PUT with an anti-tampering mechanism, and once the call is established, the local exchange of destination sends the signature received from the PUT to the gateway. 19. Method, as claimed in claim 7, characterized by the fact that after step (d) , subscriber B being a PUT with an anti-tampering mechanism, the gateway (control and billing unit 3 ) provides connection and disconnection of calls based on analyses of the PUT signature/anti-tampering signals.