RU2740299C2 - Method of subscribers connection and device for implementation thereof - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to subscriber connection and device for its implementation. For this purpose, interaction of switching unit SSP with network node, performing connection functions of subscribers over network with packet switching, which interacts via coordinated program APIs with a mobile device MS/UE of a called subscriber over a packet switched network and with server-side software and hardware network node OTT of application of called subscriber performing conversion of connection setup data with circuit switching into data of connection establishment with packet switching.

EFFECT: technical result is possibility of changing call charging, which is carried out in IMS domains of both operators as a traditional voice call in case, when a voice call is made over IP networks, which significantly reduces costs of a cellular operator NP for making calls by a subscriber by reducing payments to operators for partners for transit and "landing" ("termination") of voice traffic.

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Description

The invention relates to the field of telephone communications, namely to methods of increasing the economic efficiency of communication operators NP (Network Service Provider) when making calls by subscribers and can be used in telephone networks with intelligent control IN (Intellectual Network), in new generation networks (Next Generation Network ), in mobile networks (2G, 3G, 4G / LTE) with intelligent control CAMEL (Customized Applications for Mobile networks Enhanced Logic), including IMS (IP Multimedia Subsystem) networks.

At the current level of technology, the architecture of the core network CN (Core Network) of mobile networks (clause 3.2.3 of the GPP TS 23.002 Technical Specification standard) includes two main domains - signaling CS (Circuit Switched Domain) and packet PS (Packet Switched Domain), also distinguish layers called signaling and packet network. The standard defined (clause 3.3.1) that the signaling network includes a set of objects that support SS7 signaling (SS7 - Common Signaling Channel No. 7 or Signaling System No.7) and are processed on standardized nodes - MSC, GMSC, VLR, HLR historically called a circuit-switched network. The standard classified objects (GPRS network packets) with independent routing processed at PDN nodes GW, S-GW, MME, SGSN, traditionally called a packet-switched network, to a packet network (clause 3.3.2).

It is noted that the IMS standard excludes the CS Core network from the network architecture and splits into parts that process either only voice information or only packet data. The IMS architecture also does not support ISUP (Integrated Services Digital Network User Part) connection establishment, and uses the SIP (Session Initiation Protocol) protocol for session management.It is also noted that SS7 signaling protocols are superimposed on the IP (Internet Protocol) stack and SIP traffic is tied to standardized network nodes of cellular networks and unique identifiers MSISDN, IMSI, IMEI, which are used in cellular networks and are associated with the provision of services and charging. Thus, SIP traffic of cellular networks , including the IMS architecture, is geographically tied to the international transit switches ITC (International Telecom Commutator) and is linked by QoS (Quality of Service) indicators. Therefore, in the context of the application, the IN and IMS section of the cellular network performing SIP connection establishment, ISUP is defined as a circuit-switched network.

Traditional services of MRS (Mobile Radiotelephone Communication Network) are provided by the communication operator through the signaling network controlled by it with circuit switching with guaranteed quality of QoS communication, known as a set of signaling protocols (SIP, ISUP, etc.) of common channel signaling No. 7 OKS7 (clause 102, GOST R 53801-2010) SS7 (3GPP TS 28, 29 series).

The heterogeneous packet-switched services provided to the subscriber are performed without direct contact with the NP. This technology in cellular networks is usually called OTT (Over the Top) services.

Services Skype, Viber, Google Talk, Facebook Messenger, WhatApp, etc. use the GR protocol stack to transfer data from sender to recipient and, as you know, work on a client-server or peer-to-peer architecture in a packet-switched network. The client part of the program code of these services, which runs on MS / UE (Mobile Station / User Equipment) mobile phones, is called an OTT application.

For mobile networks, the roaming service and procedures are well known - the provision of cellular services to a subscriber outside the service area of the subscriber's "home" network using the resources of another (guest) network. The price that the subscriber pays to the operator for the provision of voice services provided by the technical means of the circuit-switched signaling network includes the cost of voice traffic "passing". Voice and signaling traffic can be charged by both the throughput traffic operator and the home operator. In the second case, the home operator reimburses the costs of servicing the signaling traffic to the operator passing this traffic through its network. If the subscriber calls to the phone of a subscriber in another network, then a separate fee will be charged for receiving - "landing" or "termination" of this call in another network from the operator of the calling subscriber. Carrying out settlements between operators requires a preliminary mutual agreement between them, and for their implementation, operators use the TAP (Transferred Account Procedure).

OTT applications using the DP protocol do not require a dedicated channel for signaling, in case of a malfunction on specific nodes D? networks can reroute packets to bypass bad sections. The SS7 signaling system and the signaling protocol stack, connects the elements of the digital telecommunication networks MSC, GMSC, VLR, HLR used to establish connections in cellular networks and are standardized by the 3GPP, ITU-T and ETSI organizations. Thus, now, in order to make a traditional voice call to a "home" subscriber located in another network, the operator has to pay for the transmission of signaling traffic through the chain of international nodal switches MSC - ITC. While for the packet GPRS / 3G / 4G / 5G traffic transmitted to its subscriber, the operator pays only to the operator's roaming partner in which his subscriber is located and does not pay anything when the subscriber uses local Wi-Fi connection points.

The proposed method for connecting subscribers and a device for its implementation is aimed at eliminating this drawback by eliminating the cost of servicing signaling traffic in transit and guest networks.

Known from patent sources application WO 2007089586 describing an interworking method for combining a circuit switched call and an IP multimedia subsystem, which invites the first remote user having independent circuit switching and packet switching functionality to join a session requiring the use of functionality such as circuit switching and packet switching, set up circuit-switched and packet-switched bearers responsive to receiving the invitation, receive circuit-switched functionality and packet-switched functionality at the gateway, combine circuit-switched data and packet-switched data for a second remote user, configured to receive merged data.

The disadvantage of this method is the need to combine the data of the signaling network (circuit switching) and the packet network (packet switching), which in turn entails the need, firstly, for both operators to deploy an IMS network, and both subscribers have mobile phones (WRTU in terms of the application) with registration in the IMS network. Secondly, the method provides for double conversion of signaling traffic into combined and VoIP traffic. And thirdly, irrespective of the fact that the voice call is performed over IP networks, the call is charged in the IMS domains of both operators as for a traditional voice call. the call on the side of the called subscriber 10 "lands" through the SIP proxy server 20 P-CSCF (Proxy-Call Session Control Function), which functionally can also maintain CDR (Charging Detail Record) billing records for subsequent TAP settlements.

The technical task of the proposed method for connecting subscribers and the device for its implementation is a significant reduction in the costs of the mobile operator NP for making calls to the subscriber by reducing payments to partner operators for transit and “landing” (“termination”) of voice traffic.

The technical problem is solved due to the method of connecting subscribers in accordance with which the cellular operator receives data from the calling subscriber to make the connection to the called subscriber on the network node for managing connections with circuit switched SSP IN / CAMEL network or CSCF IMS network, after whereby the cellular operator at the network node interacting with the network node for managing circuit switched connections, with the mobile device MS / UE of the called subscriber and with the server software and hardware network node OTT of the application of the called subscriber over the packet-switched network, determines the possibility of making the connection by technical means packet-switched network by performing a network request-response to the mobile device MS / UE of the called subscriber over a packet-switched network or by performing a network request-response to the server software and hardware network node of the OTT application of the called subscriber, p When this capability is established, the call is routed to the network node making the packet network connection, which converts the circuit-switched data into packet-switched data, and performs the connection with the packet-switched network hardware.

The technical problem is solved by a cellular network device for implementing a method for connecting subscribers, including standardized elements of the network architecture of IN UMTS (3G) networks or IMS LTE (4G) cellular networks, including the mobile device of the called subscriber MS / UE and a network node performing connection management functions subscribers with circuit switched SSP IN networks or CSCF IMS networks, additionally contains a network node interacting with it over a circuit switched network using SIP protocols, an ISUP network node that performs the functions of connecting subscribers over a packet switched network that interacts with the mobile device of the called subscriber using agreed APIs over a packet-switched network and with a server hardware-software network node OTT of the called subscriber application, configured to convert circuit-switched connection establishment data into packet-switched connection establishment data, and configured to establish connection of connections by technical means of a packet-switched network.

The invention is illustrated by drawings:

FIG. 1 depicts a cellular network device in a generalized architecture of IN and IMS networks for performing a method for connecting subscribers.

FIG. 2 shows a network dialogue of elements of a cellular network for performing a method for connecting subscribers.

In the figures, for the sake of simplicity, the radio interface section NP is not indicated and some standardized network nodes are the service control SCP (billing node) of the HLR / HSS subscriber database and others. The network dialogue between the SSP (switching node) connection control node and the SCP node is omitted. The standard interfaces for the interaction of some of the network elements in the figures have also been omitted for simplicity and publicity. SIP signaling connections, SS7 ISUPs, or the signaling domain / control plane are shown with dashed lines in IMS definitions. Packet and media RTP traffic or user level of transmission (packet domain / user plane) of IMS data with continuous lines. In the figures and in the description, the called home (homeNet) subscriber of operator NP A is designated by the letter A (MS / UE A), the caller of any operator NP is designated by the letter B. The guest NP network in which subscriber A is located and served is designated by the letter C - NP C.

The method proposed by the authors can be implemented in IN and IMS networks (Fig. 1) due to the interaction of the additional software and hardware SCP QNECT node with the SSP A node performing the functions of managing circuit switched subscribers, the SSW node performing the functions of controlling packet switched subscribers and OTT servers are part of OTT services.

The SCP QNECT network node in the architecture of IN networks is a network node SN (Service Node) of services, endowed with appropriate functions in the definitions of IN networks (B.Ya. Likhtzinder, M.A. Kuzyakin, A.V. Roslyakov, S.M. Fomichev "Intelligent communication networks" Publishing house Eco-Trend 3 Moscow 2002 p. 46). In the IMS definitions of SCP networks, QNECT is the AS (Application Server) that interacts with the S - CSCF (Serving Call Session Control Function) logical element via SIP. In the IMS network, SCP QNECT performs the functions of servicing and modifying SIP sessions (AB Golshtein, BS Golynthein Softswitch Publishing House BHV-St. Petersburg 2006, p. 330).

In the preferred embodiment, the SCP QNECT is located within the perimeter of the core CN network of operator NP A and interacts with SSP A via agreed APIs. In IN networks, such interaction is organized due to the program logic of the O / T / N-CSI trigger on the MSC when processing an incoming call. In the IMS network, the interaction between SSP A-SCP QNECT and the need to route the SIP session to the SSW is organized by the IFC (Initial Filter Criteria) rule that determines the need to re-route the SIP session of the incoming call.

To determine the presence of subscriber A in the IP network (with packet switching) by performing a network request-response PING1, the program logic of the SCP QNECT node is coordinated with the software module of the MS / UE mobile device A using the program APIs. To establish a connection over OTT networks of SCP QNECT applications interacts with the server side of OTT services. Such interaction is organized according to the agreed API to receive its data and determine the presence of the subscriber in the OTT service network through the PING2 network request-response.

SSP network node A is a standard network IN connection control node (MSC). In the IMS network definitions, SSP A performs the Serving / Proxy / Interrogating P / I / S-CSCF session control functions. As the P / I / S specialist understands, the CSCF functionality can be divided into separate independent network nodes. For simplicity, the MSC / P / I / S / CSCF network nodes are designated in one functional block because in general, subject to the IN and IMS standards, they include similar call control functionality.

SSW A (Softswitch) network node in terms of IN and IMS networks is generally SG (Signaling Gateway) - a network node that coordinates the exchange of messages between networks. In general, SSW A is a soft switch used to provide full-fledged analogue (circuit-switched) and IP-telephony (packet-switched) services. Supports all protocols required for IP telephony. By definition, SSW A is endowed with the P-CSCF for SIP session modification. The software logic of the SSW A node is configured to extract the message data of the SIP, ISUP protocols and establish a VoIP voice call connection (VoIP server) over the IP network through the software module on the MS / UE A. To process calls to the public PSTN network, SSW A performs the functions of a VoIP gateway ...

The mobile device MS / UE A homeNet of the subscriber is generally an IP-phone, VoIP-phone, SIP-phone that allows users to organize voice communication over circuit-switched cellular networks and over IP-networks with packet switching. MS / UE A standardly supports RTP (Real-time Transport Protocol) for audio data transmission and corresponding codecs known from the prior art and used in cellular networks and IP networks. In the visited NP C of the network, the MS / UE A is served by the SSP C (VMSC / P-CSCF). HomeNet subscriber A in the NP C guest network can receive RTP voice traffic over a circuit-switched network through standardized SS7 network nodes using standard SIP connection protocols, ISUP, in the figures and further denoted RTP1. Packet TCP / IP traffic, MS / UE A receives through a standard IN node of SGSN / GGSN networks or IMS gateway P-GW C for access to external IP packet-switched networks serving RTP traffic of OTT applications. In the figures and below, this traffic is referred to as RTP2.

The MS / UE A software part has been modified by the PING1 receive-response module at the request of SCP QNECT. Such a refinement can be accomplished by providing additional software modules (updating) to the OTT application installed on the MS / UE, a separate OTT application, an STK SIM applet, or in another way known from the prior art. In general, such a module performs the function of establishing a connection using the assigned SIP URI. Receiving an incoming call with drawing the screen of an incoming call and standard processing of audio RTP traffic. In a particular case, as one of the implementations, such a module can be functionally included in the standard OTT application of the subscriber's personal account of the NP A-LOGIN A.

OTT servers - the server part of OTT services, are standard server network nodes, the program logic of which performs information storage and data processing. The server part ensures the security of the logins and passwords of its users, allows you to query about the data of your users' contacts and determine the fact of their presence in the OTT service network. In the context of the application, OTT servers act as VoIP servers and VoIP gateways for transmitting audio data over RTP.

NPn designates transit telecommunication networks serving SIP ISUP RTP1 traffic on the ITC (International Telecom Commutator) switching nodes.

The dialogue of network nodes for performing the proposed method for connecting subscribers is illustrated in the diagram of FIG. 2.

The SSP A connection control node receives requests to establish an incoming homeNet call to subscriber A located in the NP C guest network - 1 ISUP IAM from subscriber In the public PSTN network or 2 SIP INVITEs from subscriber B of any operator. On the SSP switching node A in the IN network, a subscription trigger is triggered when processing incoming T-CSIINIT calls. The IFC INIT call filtering rule is triggered on the CSCF session management server in the IMS network. When they are triggered, the standard program logic SSP A makes a request to SCP QNECT to receive data on further processing of the 3 API ROUTING INFO call.

Next, the first version of the LOGIN CONNECT connection is performed, which provides for a network request-response to MS / UE A for its presence in the IP network 4 PING1 REQ. SSW A translates 5.6 UP LINK PING1 to the SIP URI assigned by MS / UE A to be on the IP network. After the PING1 processing module responds, MS / UE A responds with 7.8 DOWN LINK PING1. SSW A returns a positive 9 PING1 RESP to SCP QNECT. The SCP QNECT software logic establishes the presence of the SIP URI login in the IP network, the MS / UE's readiness to receive a voice call via RTP2 and sends the SPC (Signal Point Code) code of the SSW A node to SSP A for further call processing - message 10. SSP A performs routing call 1,2 to node SSW A - messages 11,12. According to the program logic, SSW A connects a voice call in the IP network to the SIP URI of the login message 13-16. By the graphic functions of the MS / UE A operating system, by the commands of the LOGIN A program module, the screen of the incoming INCOMING CALL is drawn. After subscriber A answers, the RTP2 17 audio traffic is transmitted in the packet-switched IP network.

The second connection option is shown in the section of the OTT CONNECT diagram (Fig. 2). After SSP A's request for further processing of call 3, SCP QNECT polls the OTT servers of partner networks about the presence of subscriber A in their network - 18 API PING2 REQ. The number of such networks (OTT services) depends on the operator's agreements; in the particular case of the implementation of the method, these are the most popular OTT messengers. The program logic of the sequence of polling of OTT servers may depend on the technical or marketing preferences of the operator. In the simplest particular case, the first positive response from the OTT server 19 PING2 RESP, which confirmed the presence of the subscriber in his OTT INIT network, results in the issuance of message 20 to SSP A with the SPC address of the current OTT server for routing. SSP A normally routes 21,22 to the specified OTT server address. Further, the current OTT server, according to the standard logic of the VoIP server, establishes a connection with the SIP URI of subscriber A in his network - messages 23-26 After completing the connection, subscriber A observes the screen of the incoming call in the graphical interface of the OTT application -INCOMING OTT CALL and after the OTT answer the network provides the transmission of 27 RTP2 audio data.

As a specialist understands, the proposed connection options LOGIN and OTT CONNECT can be performed in any order to serve one call of a subscriber located in the NP C guest network. In the absence of a SIP URI identifier in the IP network, i.e. no response for both polling options PING 1 → MS / UE A and PING2 → OTT servers, SCP QNECT determines the absence of subscriber A in the IP network (SIP URI) and sends a CONTINUE response to SSP A (not shown in Fig. 2) to continue processing call without parameters. In this case, SSP A uses the standard incoming call processing logic to make a circuit-switched network connection through NPn transit networks and ITC switches. (upper route SIP, ISUP Fig. 1) with subsequent transmission of audio data RTP1.

As demonstrated above, the method of connecting subscribers proposed by the authors significantly saves the operator's expenses for servicing traffic in transit networks, eliminates the need for agreements with transit operators and the laborious exchange of TAP data for mutual settlements. Software revision of the subscriber's MS / UE A homeNet, in terms of installing the LOGIN module for connecting LOGIN CONNECT and receiving RTP2 audio data, is performed remotely and is organizationally and technically not difficult. To perform the OTT CONNECT connection, a not laborious coordination of the interfaces of the control node of the SSP A connection and the OTT server is performed, which, taking into account the similar protocols for establishing SIP connections and RTP data transfer, is not difficult.

For subscriber A's homeNet, for obvious reasons of cost savings in roaming, the proposed connection method is preferable to the traditional signaling connection (landing or termination) of the call. Implementation of the graphical interface of the incoming call screen with the standard graphical functions of the MS / UE operating system ensures the transparency of the connection for the subscriber.

As a specialist understands, the proposed method can be used, including for sending SMPP SMS USSD messages.

The proposed method in both variants of the connection was tested by the applicant in the network architecture of a well-known cellular operator based on the SCP QNECT complex and confirmed the claimed technical effect and the operator's QoS requirements for the quality of subscriber service.

Claims (12)

1. A method for connecting subscribers, in accordance with which a cellular operator, by technical means of a circuit-switched network, receives data from a calling subscriber to make a connection to the called subscriber, characterized in that after receiving this data at the network node for managing circuit-switched connections, the cellular operator determines the ability to make a connection using the technical means of a packet-switched network, when such a possibility is established, routes the call to a network node that performs the connection by means of a packet-switched network, which converts the circuit-switched data into packet-switched data and performs the connection with the technical means of a packet-switched network. 2. The method according to claim 1, characterized in that the circuit-switched connection control network node is an SSP IN service control network node. 3. The method according to claim 1, characterized in that the circuit-switched connection control network node is a session control network element CSCF of the IMS network. 4. The method according to claim 1, characterized in that determining the possibility of making a call by the technical means of a packet-switched network includes performing a network request-response to the mobile device MS / UE of the called subscriber over the packet-switched network. 5. The method according to claim 1, characterized in that determining the possibility of making a call by the technical means of a packet-switched network includes performing a network request-response to the server software and hardware network node of the OTT application of the called subscriber. 6. The method of claim 1, wherein the packet-switched connection control network node is a network node that interacts with the circuit-switched connection control network node and the called subscriber's mobile MS / UE over the packet-switched network. 7. The method according to claim 1, wherein the packet connection control network node is a network node that interacts with the circuit switched connection control network node and the called subscriber application OTT server firmware. 8. A cellular network device for implementing a method for connecting subscribers, including standardized elements of a network architecture of a cellular network, including a mobile device of a called subscriber and a network node that performs the functions of managing circuit-switched subscriber connections, characterized in that it additionally contains an interacting with it over a circuit-switched network, a network node that performs the functions of connecting subscribers over a packet-switched network, interacting with the mobile device of the called subscriber over the packet-switched network and with the server software and hardware network node OTT of the called subscriber application, configured to convert the connection establishment data with circuit-switched into packet-switched connection establishment data; and configured to establish connections by the technical means of a packet-switched network. 9. The device according to claim. 8, characterized in that the standardized elements of the network architecture of the cellular network include network nodes IN UMTS (3G) networks. 10. The apparatus of claim 8, wherein the standardized elements of the cellular network architecture include IMS LTE (4G) network nodes. 11. The device according to claim 8, characterized in that the interaction of the network node performing the functions of managing circuit-switched connections and the network node performing the functions of connecting subscribers over the packet-switched network is carried out using the SIP, ISUP protocols. 12. The device according to claim 8, characterized in that the interaction of the network node performing the functions of connecting subscribers over a packet-switched network with the mobile device of the called subscriber and with the server software and hardware network node of the OTT application of the called subscriber is carried out using the agreed API.

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