RU2677851C2 - Method of notification of canceled call - Google Patents

Abstract

FIELD: information technology.SUBSTANCE: invention relates to the field of informing subscribers about the occurrence of network events, and specifically to a method for notifying a subscriber of a canceled incoming call. Telecommunication provider accepts the outgoing call of the calling party, determines the number of the called party, in case of cancellation of the call by the calling party before informing the called party about this call, telecommunications provider detects the canceled call, determines that the called subscriber is not informed about the canceled call, and generates an information message about the canceled call to the called subscriber.EFFECT: bringing to the called user a notification about the call attempt reset by the first subscriber at any stage of establishing a connection in the operator’s signaling network using any call switching protocols.3 cl, 4 dwg

Description

The invention relates to the field of telecommunications, in particular to methods of informing subscribers about the occurrence of network events generated by subscribers and can be used by operators of the intelligent network NP (Network Provider) in SPRS (mobile radio communication networks) of virtually any type - GSM, UMTS, LTE and others.

In accordance with the current level of technology, two levels are common to all types of communication networks:

- signal level - a set of messages and signals that is used by participants in a communication network (end-user devices and network nodes) to perform registration operations, make a call, confirm readiness, and possibly about the features of supported communication types (voice, video, encoding method) , signals of confirmation of the beginning or end of the conversation, signals of the reorganization of the channel, signals informing the parties (nodes) involved in the organization of communication, information about the quality and charging; in digital networks it is also used to transmit information about services allowed to the user and other information necessary for the operation of the communication network;

- media level - the level of organization of the exchange of voice or video information encoded in digital format, may allow intermediate transcoding of signals at intermediate nodes, when switching from network to network or while providing additional services.

The indicated logical separation into the signal and media level is true both for the most modern types of OTT communication networks (Over-the-Top, over the IP access network - Internet), such as Skype, Viber, GoogleTalk, Facebook Messenger, WhatApp, and for the classic types communications described in telecommunication standards ITU-T, ETSI, 3GPP and other institutions.

The telecommunications provider whose network services are used for the OTT service has no control over the latter. This is due to the fact that the user is able to use the Internet the way he wants. The network operator only transfers IP packets from the source to the destination, he can only know about the packets and their contents. In addition, for the OTT user, communication is cheaper, the calling subscriber does not pay for the established telephone connection and rent of the established communication channel.

At the same time, although the TCP / IP protocol is a reliable means of data transfer, nonetheless standardized communication protocols (signaling protocols of mobile radio communication systems SPRS) provide guaranteed QoS standards. In this regard, it is interesting that the individual functions of the OTT communication guarantee a more reliable response than the signal network of the operator (without taking into account the response time). One of such applied consequences of OTT communication is the guaranteed notification of the canceled call to the second subscriber by the first subscriber to the second end user of the OTT application. This is the case when the first subscriber in the OTT application dials the number of the second subscriber and quickly cancels it based on his motives. In this case, the packet OTT communication network works in the usual TCP / IP protocol mode and ensures delivery of TCP / GR packets with the interface of the corresponding OTT application to the end device of the second subscriber, notifying him of the call attempt. In a carrier’s signaling network, any operation performed by a user agent client (UAC) is implemented through a series of transactions. Dialogs to establish a connection are created by returning answers that do not inform about errors to requests of certain types. If the call is dropped by the first subscriber, for example, in accordance with the SIP Session Establishment Protocol standard, the connection dialogue is interrupted by the BYE message. When a BYE message arrives at a conversation participant, all sessions associated with this conversation must be destroyed. The UA agent client of the first, calling user can send BYE both in the established dialog and in the dialogs that are at an “early stage”. For example, if the first subscriber cancels the call while establishing a connection with the forwarding server, at the moment when the forwarding server requests the current address of the called user. In this case, the server forwarding to the BYE message, terminates the dialog for establishing a connection with the first subscriber, releases resources and responds with a 200 OK message to the first subscriber, confirming the release of resources. The connection with the second user is not established, and he is not notified of the discarded attempt to call the first subscriber.

This property of the signaling protocols SPRS illustrated by the example of the SIP protocol, but not limited to them in the framework of the present invention, seems to the authors to be incomplete from the point of view of both users of SPRS and telecom operators. The present invention seeks to remedy this drawback. Namely, to reliably bring to the called user a notification about a call attempt discarded by the first subscriber at any stage of establishing a connection in the operator’s signal network using any call switching protocols known in the art.

US patent 5859903 01/12/1999, describes a method of notification of a call dropped by the first subscriber in a wired (applied for this invention) telephone network containing the so-called a service node of a push-button telephone network connecting telephone sets and individual communication lines. The method includes the steps of a service node verifying a call from one of the connected communication lines; whether a call is made to the extended connection of subscribers subscribed to the service; whether the called subscriber with an “extended” connection did not answer the call. If the answer is a check according to these steps, then the receipt of the identifier of the caller (first subscriber) is checked, it is saved and sent to the called subscriber.

With the current level of technology, the disadvantages of this method are obvious: wired, bus connection, the so-called. office lines to the notification device; separate, so-called “Extended” connection of subscribers subscribed to the service (“outputs of extension line subscriber 1-n ...”); the impossibility of scaling, performance management, not the flexibility of the solution.

The state of the art application is known WO 2014/087269 2014.06.12 describing a method for routing calls from OTT communication networks to OTT networks and to networks that are not related to them. According to the method, the caller’s operator receives the dialed number of the called party, transmits this number to the OTT provider who checks the ability to complete the specified call, and then the test result is transmitted to the communication operator, ensuring uninterrupted communication for the calling and called party. Due to this, the authors achieve what they call a "seamless" connection of subscribers of OTT networks and ordinary TTN networks.

This method provides routing of a call, including a call interrupted by the calling party, due to the fact that packet data transmission in this case ensures message delivery over the signaling network of the operator. The disadvantage of this solution is also obvious, by definition it works only in OTT networks with the corresponding consequences - the need for an OTT application for at least the first subscriber and the impossibility of QoS compliance with the standardized in the SPRS. In addition, this solution does not provide interaction between different OTTs, networks, for example, Viber and Skype, etc.

The technical result of the proposed method of notification of a canceled call is a quick and reliable notification of the called subscriber about the canceled attempt to call the caller in the SPRS.

The technical result is achieved by the method of notification of a canceled call, according to which the telecommunication provider receives an outgoing call of the calling party, determines the number of the called party, and if the call is canceled by the calling party before informing the called party about this call, the telecommunication provider detects the canceled call, determines that the called subscriber is not informed about the canceled call and generates an information message about the canceled call to the called subscriber. Moreover, in accordance with the method, a canceled call is detected both with the help of a node additionally included in the network of a cellular communication operator and with the help of a standard network node of a cellular communication network operator.

The method is illustrated by drawings:

In FIG. Figures 1 and 2 show a simplified SPRS scheme with options for connecting an additional SCP XDRay node. FIG. 1, 2 do not limit the methods of connecting the SCP XDRay node to the SPRS architecture, but illustrate the two main possible connection options within the framework of this invention.

In FIG. 3 is a diagram of a canceled call notification dialog in the CAP listening mode of the SSP-SCP dialogue.

In FIG. 4 is a diagram of a canceled call notification dialog in the mode of listening to alarm messages using the example of ISUP.

In the figures, the signal network is shown by dashed lines, the data network by solid lines.

The specified method can be implemented in SPRS of various ITU-T standards, FIG. 1 illustrates generalized networks NP A, B, including interacting main nodes - mobile terminals of subscribers of MS; SSP service switching nodes, in different SPRS architectures, its functions are performed by MSC, MME, etc .; SCP service management node performing billing functions; SCP XDRay node providing additional types of VAS services IN and connected to the operator’s core network. Some standardized LSS nodes are the BSS base station system, gateway nodes GW, etc., for the sake of simplification in FIG. 1 are not shown. Also to simplify FIG. 1 it is accepted that the registers VLR, HLR, HSS, as well as SMSC are part of the SSP.

Within the framework of the proposed method, but not limiting the scope of its legal protection by the hardware-software part of the Far East Military District node, the PAK SCP XDRay appears. This method can be implemented by various architecture of the PAC, which is both a separate SPRS node and part of the existing standardized network node. SCP XDRay - a complex for notification of events of subscriber behavior in cellular networks developed by the authors - application WO No. 2013107454. The complex can be passively connected to the operator’s network and can be configured to capture any dialogs of the operator’s core network, the program logic of its work, which is the know-how of the authors, is optimized for instant response to captured events and is configured according to the time of the formation and transmission of notification messages to the network and the possibility of their reception subscribers or operator. The parameters of the subscribers are extracted from the intercepted messages and are compared with the data of the subscriber profile using a special algorithm of the software package to generate a notification method. In various architectures, SCP XDRay can listen to network communications while interacting with the gateway node, the switching node as in FIG. 1, SCP or by connecting to the physical network of the ATP through the generic gateway of FIG. 2. The hardware and software architecture of SCP XDRray is optimized for instant response to events of the operator’s signal network in a capture-storage-notification link, with the PAC providing such link in various combinations.

FIG. Figure 3 illustrates the implementation of SCP XDRay's CAMEL technology. In this embodiment, SCP XDRay in passive mode listens to the CAP's SSP-SCP dialogue. In accordance with the paradigm of the basic model of call state (BCSM), the call processing process in SSP moves from one call state to another (PIC - Points in Call). Access to IN services for specific PICs is defined as the so-called trigger points detection point DP. CAMEL Subscription Information (CSI) can be subscribed to in the HLR subscriber profile or directly on the SSP (Network Service CAMEL Subscription Information, N-CSI). Outgoing call processing takes place on the SSP (Vistor MSC) in which the subscriber is currently registered. The VLR of this MSC already contains a copy of the subscriber’s profile, which means a subscription to the dropped call notification service. In another embodiment, the notification of the dropped call may be the predefined functionality of the SPRS and provided without a subscription. Subscriber A initiates an outgoing call, after an SSP-MS signal exchange including a service request, in this case an outgoing call, to simplify the diagram of FIG. this dialog fits into the 1 Setup message. An initial DP call state is formed, which means that a call to intelligent services is detected and the SSP-SCP dialogue begins. The SSP initiates a request 2 InitialDP (A, B) to the SCP address with a request for instructions on processing the call. After analysis, the SCP responds with a message 3 RRB \ ACH ... \ CONt "RequestReportBCSM + Continue + ApplyCharging" with billing permission. At this time, the call sequentially transitions to the PIC "O_Null & Authorize Origination_Attempt" state, including verification of subscriptions, call barring, etc .; “Collect_Info”, “Analyse_Information” - analysis of subscriber subscription data analysis of called number; "Routing & Alerting" including the call of subscriber B. In the case of a response of the called subscriber, the call goes to the state of DP "O_Answer" or other DP depending on network events - the subscriber is busy, does not answer, etc., in accordance with the recommendations of ITU- T Q.1214. SCP XDRay monitors the entire dialog in mirror traffic in passive mode (Fig. 1). If at the moment of the SSP A - SCP A dialogue, subscriber A cancels the call, pressing the hang up key MS A sends 4 REL message to the network. The SSP generates an O_Abandon event indicating that the calling party releases the call before the call reaches the active phase, in which the called party is notified of the incoming call, “Routing & Alerting”, for example, and sends the corresponding 5 O_Abandon message to the SCP. This event can occur during creation of the BCSM located in the PIC or Null, or during the interaction with the user at the beginning of the call (BCSM is in the collected DP information) and does not contain a reason code in the failure notification, i.e. the message can be sent to the dialog S SP - SCP at any stage of the signal exchange up to CAP message N (in Fig. The messages "CAP message N-1" and "CAP message N" are not numbered because in this case the dialogue is interrupted they are not transmitted). SSP releases the establishment resources connects and sends an RLC confirmation 6. SCP XDRay intercepts the O_Abandon message and starts the notification procedure for subscriber B. PAK SCP XDRay sets up a signal dialog 7-14 to notify the called subscriber B. Immediately after receiving confirmation SSP B, the address is complete and the program algorithm generates a disconnect message 8 REL (A, B). Subscriber B is notified of an attempt to call subscriber A. Additionally, SCP XDRay can send an SMS notification to subscriber B 15-16.

Such an implementation of the method is preferable and without limiting the scope of legal protection is the main mode of operation of SCP XDRay. SCP XDRay's passive mode is limited to listening to alarms, and the SSP is exempted from disconnected call reject notification switching. It provides the principles of component construction of an IN network, separates the functions of switching and call service management. The implementation eliminates the signal exchange between the SSP switching node and the XDRay SCP node providing VAS services, which is certainly preferable from the point of view of SPRS service.

FIG. Figure 4 illustrates the ISUP signal exchange diagram in which SCP XDRay in the passive mode listens for signal traffic using the ISUP example and notifies the called party B. In this implementation, SCP XDRay passively listens for signal exchange (ISUP) in the operator’s core network outside the CAP SSP-SCP dialog.

Subscriber A initiates an outgoing ISDN call MS A sends a Setup message 1 to outgoing SSP A. Upon receiving a connection request from a caller, outgoing SSP A analyzes the route information and generates an initial IAM address message. The IAM message transmits address information, as well as information related to the establishment of the connection, compatibility parameters, etc. SCP XDRay intercepts the 1 Setup signaling message to initiate the connection establishment procedures and marks the subscriber profile A signifies the outgoing call establishment procedure, this is possible due to the preliminary accumulation of subscriber profiles on SCP XDRay. If subscriber A cancels the outgoing call and drops it (hangs up), MS A sends 2 REL message to the network - release message of the channel used in the connection, the message informs SSP A about the need to release the resources involved in establishing the connection. SSP A by the reason code (ISUP cause codes), in this case 16-normal call termination at the request of MS A, ensures the transition to the initial state of the elements of the connecting path and sends a confirmation 3 RLC. In this case, SSP A does not guarantee sending an IAM message in the direction of called party B to the incoming SSP B or transit SSP, and therefore does not guarantee that subscriber B is informed of the call attempt. SCP XDRay intercepts REL 2 message; its software algorithm links the received disconnect message from MS A with the active sign of the subscriber profile - “outgoing connection is established”. Based on REL ISUP cause codes = 16, as well as on the condition that the operator doesn’t see the initial IAM message and / or request additional INR information, answer outgoing SSP A - INF, and / or confirm the switch - the address is sufficient for AFM, software SCP XDRay determines that Subscriber B is not informed of the dropped call. And it starts the process of notifying subscriber B. PAC SCP XDRay establishes a signal dialog 4-11 to notify the called subscriber B. Immediately after receiving confirmation of SSP B, the “full address” program algorithm generates a 8 REL disconnect message (A, B). Subscriber B is notified of an attempt to call subscriber A. Additionally, SCP XDRay can send an SMS notification to subscriber B 12-13.

Such an implementation of the method may be relevant if it is impossible to listen to the ATS dialogue. The implementation also eliminates the signal exchange between the switching node of the SSP and the node of the VAS services, which is certainly preferable from the point of view of service SPRS. The drawback and payment for such a separation of functions, in this method of listening to signal traffic, is the increased load on SCP XDRay in terms of monitoring all outgoing calls and controlling their completion. Even taking into account that the software algorithm of SCP XDRay is optimized for instant write-reading of the sign of establishing an outgoing connection of the subscriber profile, the load on the server is estimated as significant.

As is clear to a specialist, using the ISUP protocol as an example, this method can be used not only in SPRS networks, but also in public telephone network networks of PSTN.

The method can be implemented in semi-active mode (less preferred). In this case, the signal exchange between SCP XDRay and SSP or / and SCP A is turned on. And after interception and processing of the O_Abandon message, SCP XDRay exchanges data with SSP or / and SCP A to switch the notification of the called subscriber. In this case, the initiation and termination of the connection (messages 7-16 of Fig. 2) to notify the called subscriber is performed on SSP A. The essence of the method also involves notification of the dropped call without the SCP XDRay node. In this case, the signal exchange 7-16 of FIG. 2 is performed between SSP A and SSP B. A SCP XDRay is either absent from the network architecture or performs other functions (provides other services). In this case, the generalized logic of processing the end of the calling party and notifying the called is performed on SSP A and / or SCP A.

The capabilities of SCP XDRay PAK provide an implementation of a method in which operator radio network messages are analyzed, for example, via DTAP GSM (Direct Transfer Application Part) protocol and / or lu interface with CS channel switching, PS packet switching for networks to detect a canceled call and to notify about it. LTE In this case, the SCP XDRay node receives mirrored operator network radio traffic on the MS-MSC (GSM), UTRAN-CN (LTE) section. This implementation option is preferable in terms of the speed of the method, in it message delays on the switch and in the operator’s core network as a whole do not affect the notification speed. In this case, the general logic of the method is preserved, taking into account the formats of the protocols (interfaces) used in the radio network SPRS.

The implementations described above illustrate some of the many implementations of the notification method, it is obvious for a specialist that the essence of the method is implemented not only through CAP / ISUP smart call control punctures, but also through the SIP session establishment protocol, for this, the SIP server is included in the SCP XDRay PAK. The logic of the SIP method execution is similar to that given above, taking into account the SIP API standards and in general, consists in generating an SCP XDRay notification before the end of the establishment of the SIP session when it is interrupted by the caller. The paradigm of the proposed notification method fits well with other call switching methods known in the art.

Notifications to the called subscriber can be generated as SMS, USSD, PUSH messages, in any other formats known from the current level of technology.

This method is implemented and operated by the applicant in the SPRS of a well-known operator based on the SCP XDRay complex and has shown the effectiveness of reliable notification of subscribers of a canceled call in accordance with standardized QoS requirements.

Claims (3)

1. The method of notification of a canceled call, in accordance with which the telecommunication provider receives an outgoing call of the calling party, determines the number of the called party, characterized in that, in case of cancellation of the call by the calling party before informing the called party about this call, the telecommunication provider detects the canceled call, determines that the called subscriber is not informed about the canceled call and generates an informational message about the canceled call to the called subscriber. 2. The notification method according to claim 1, characterized in that the canceled call is detected using the node additionally included in the network of the cellular operator. 3. The notification method according to claim 1, characterized in that the canceled call is detected using a standard network node of a cellular network operator.

Images