Intelligent network communication system

Abstract: This invention relates to a method and apparatus for improving the performance of intelligent networks. In a departure from the prior art, when a data base system, such as a service control point (11), receives an inquiry from a switching system (2), if the data base system recognizes that it cannot provide the complete data requested by the inquiry, it directly launches another inquiry to another data base system (12) to provide the missing data. Advantageously, such an arrangement reduces the number of messages transmitted among switching systems (1,2) and data base systems (11,12,13).

Description: Technical Field This invention relates to data communication arrangements in support of telecommunication networks and more specifically in support of intelligent networks. Problem A major advance in telecommunication networks of the past decade has been the introduction of the intelligent network (IN) and the advanced intelligent network (AIN). Previous telecommunications networks consisted of switching systems interconnected by transmission facilities. The AIN enhances the capabilities of such systems by providing, in addition, data bases called service control points (SCPs) and further by providing service circuit nodes (SCNs) for customized feature and specialized call handling including querying telecommunication network customers in order to obtain additional information for controlling calls. The SCNs are each connected to an associated switching system and communicate with that switching system over both audio and data facilities while the SCPs are connected to the switching systems over a data signaling network. The data signaling network in most modern systems is a common channel signaling network using the signaling system 7 (SS7) protocol promulgated by the Consultative Committee for International Telegraph and Telephone (CCITT) or by the American National Standards Institute (ANSI). The intelligent network is used, for example, to route 800 calls. Such calls lack a dial address that directly allows the telecommunications network to determine a destination. Instead, upon receipt of an 800 number, a switch of the network equipped to communicate with the SCPs and therefore designated as a switching services point (SSP) queries an SCP to obtain information as to where to route the call. For a simple 800 call the SCP returns a conventional plain old telephone service (POTS) number, a telephone number that directly identifies the destination, and which can be used for routing the call to the destination in the conventional way. For some cases, the initial response from the initially queried SCP does not provide enough information to establish a call. Under such circumstances as described, for example, in U.S. Patent 4,924,510 the initial response from the first SCP is used by the SSP to formulate a second request to a second SCP identified in the response message from the first SCP. Such "double dipping" requires four message transmissions to obtain the information necessary for completing a call. A problem of the present AIN arrangement is that some of the increasingly complex services that are being considered today require more and more exchanges of data between SSPs and SCPs. Such multiple exchanges of data require the use of scarce resources in the SSPs and further cause excessive delay in obtaining all the information necessary for establishing AIN calls. An article entitled "Experiences of Implementation Using Advanced Intelligent Network Release 1 Architecture", by D. J. Aitken, appearing in Eighth International Conference on Software Engineering for Telecommunication Systems and Services, 30 March - 1 April 1992, describes a set of call flow "rules" to be used in providing advanced intelligent network (AIN) services where multiple features may be invoked in a single call. One such set of "rules" is associated with a "two tier" call, requiring two queries to determine call routing information. In this case, the second query carries a "rule" limiting it to a single transaction, thus avoiding an endless number of queries. Solution According to the invention there is provided a method of establishing a call in a network, and a database system for use in an intelligent network, as set out in the accompanying claims. In a preferred embodiment, in a departure from the prior art, an SCP is enhanced to recognise situations wherein it needs additional information from another SCP and directly requests that information from that SCP by sending an information request message over the signalling network interconnecting SCPs and SSPs. The second SCP then sends its response to a user of that response which may be the requesting SCP or the SSP that originally requested data or even a customer that directly or indirectly requested data. If the user is the requesting SCP, this SCP will, directly or indirectly forward data from the response of the second SCP to the SSP. Advantageously, such an arrangement reduces the number of query messages that must be transmitted from the SSPs. Brief Description of the Drawing FIG. 1 is a block diagram of an advanced intelligent network and the communications paths among the elements in accordance with this invention; and FIG. 2 is a flow diagram of a program performed in one or more of the data bases of the intelligent network. Detailed Description FIG. 1 is a block diagram of elements of an advanced intelligent network as connected in accordance with the principles of this invention. The elements shown include switching systems, in this case, SSPs 1 and 2, data base systems SCPs 11, 12, and 13, and SCN 15. The SCPs and SSPs are interconnected by signalling network 10 which transmits SS7 messages between SCPs and SSPs or other switching systems connected to the signalling network. In a departure from the prior art, signalling network 10 transmits messages between SCPs in addition to transmitting messages between SSPs or between an SSP and an SCP. The SSPs 1 and 2 are interconnected with each other and with other switching systems of the AIN by communications network 20. SCN 15 is connected to SSP 2 by both voice and signalling links. In an alternative arrangement, signalling links of SCN 15 can also be connected directly to signalling communications network 10. Each of the SSPs 1 and 2 are SSPs equipped to communicate via signaling network 10 with SCPs 11, 12, and 13. Both are program controlled switching systems controlled by one or more processors each responsive to a stored program of the processor. Each of the SCPs also includes a program controlled processor for analyzing input messages, controlling access to data stored in the SCP and formulating responsive output messages. In accordance with the principles of this invention, these output messages also include querying messages for other SCPs and the processors are responsive to messages received from other SCPs for formulating a response message to an SSP. An example of the use of this arrangement is the following, referred to hereinafter as enhanced 800 service. Suppose that there is a business which has an 800 number that is meant primarily for use by customers within a state or within a region of a state (an example of the latter might be a Chicago metropolitan area 800 number). However, the business also has a number of important customers and it wishes to encourage these customers to call using the same 800 number. The business provides each of these customers with a personal identification number so that only authorized customers can call the 800 number from out of state. Subscriber 25 is connected to switching system 2, either directly or, in the more usual case, through a telecommunications access network. The user has dialed the 800 number of the business specified above. This number, along with the caller's directory number, as identified by automatic number identification (ANI), is transmitted to SSP 2. In response to this, the switching system 2 transmits a query to SCP 11 which is a basic 800 number response data base. SCP 11 determines that this is not a valid 800 number for a customer from that area (as defined by the numbering plan area (NPA) of subscriber 25's directory number). However, SCP 11 further recognizes that this particular 800 number has some customers who are able to call that 800 number from outside the region. Therefore SCP 11 transmits a message to SSP 2 to request that the customer be connected to SCN 15 and further that the customer be prompted by SCN 15 to enter a personal identification number (PIN). The customer enters this PIN which is transmitted in a message to SSP 2 and thence to SCP 11. SCP 11 does not contain the data for verifying the PIN and therefore launches a query to SCP 12. The query is transmitted over SS7 signaling using an NCA message (e.g., a Transaction Capabilities Application Part (TCAP) message within a new field) and the message further contains routing information for the call in case the call can be completed. (This routing information would be the POTS number of the business.) SCP 12 verifies that the PIN for the customer identified by the ANI of that customer transmitted in the NCA message is proper and transmits to switching systems 2 the POTS number of the business along with an indication that switching system 2 may take further steps to complete the call to that POTS number. SCP 11 is controlled by a processor 30, operative under the control of a program 31. The processor is connected to a data receiver 32 for receiving signaling messages from signaling network 10 and a data transmitter 33 for transmitting data to the signaling network. Data for the SCP is stored in data storage 35. The data bases may be interconnected directly via the signaling network 10, or it may be more convenient to connect a data base to a switch via the signaling network, and to use the switch as a signal transfer point to relay a message to another data base via the signaling network. FIG.2 is a flow diagram of actions performed in the data bases in response to receipt of an 800 call routing request. The routing request is received (action block 200) and analysed (decision block 202). if the number is that if a basic 800 service, then the routing message is returned directly to the requesting switch in accordance with the teachings of the prior art (action block 204). If the initial data base recognises that this is an advanced call, then a query is sent to the advanced 800 data base identified in the data stored in the original data base. This query contains sufficient information so that the advanced 800 data base can send full routing information directly to the switch. The query is sent in action block 206 and the advanced 800 data base, responsive to this inquiry, sends a routing message for the call directly to the switch (action block 208). Thus, only three messages (SSP to 800 data base, 800 data base to A800 data base, and A800 data base to SSP) are required instead of the four messages (SSP to 800 data base, 800data base to SSP, SSP to A800 data base, and A800 data base to SSP) of the prior art. The advanced 800 data base can also send a response to the requesting 800 data base for the latter to return information directly to the requesting switch. If the analysis indicates that this is an enhanced 800 call as defined above then the data base transmits a message to request that the service node obtain a personal identification number from the caller and return that PIN to the data base (action block 210). This request is transmitted to the SSP if no connection has been set up between the calling subscriber 25 and the service node 15 or is sent directly to the service node if such a connection already exists. The service node will then request the PIN from the caller and will transmit that PIN to the data base (action) block 211). In the preferred embodiment, this transmission is done by means of a message which has as its destination the data base, so that the only role of the switch in the transmission of the message is to act as a signal transfer point to relay the message received from the service node to the requesting data base or, in alternative embodiments, to provide protocol conversion. In alternative embodiments, the service node replies to the switch which then formulates a separate message for transmission to the data base. In case no PIN has been obtained from the caller, the service node returns an indication to that effect instead of returning the PIN. In decision block 212 the data base compares the PIN (if any) received from the service node with the PIN stored for that caller and that particular 800 destination number. if there is a match, then the data base sends a query to the 800 data base serving the destination (action block 214) and that data base sends a routing message for routing the call directly to the requesting switch. This data base could send the information back to the original 800 data base that was queried for that data base to pass on to the switch. For this enhanced 800 service, the principles of this invention avoid the necessity of repeatedly sending intermediate messages (request PIN, PIN obtained, identity of 800 data base serving destination) to the SSP for the SSP to process and to initiate another query message. This service is just one example of a service that can be implemented more efficiently, with less processing load on the SSP and shorter call set-up times, in accordance with this invention. If either no PIN has been obtained or there is no match, then a routing message to route the call to an announcement ("your call cannot be completed" or equivalent) is returned to the switch (action block 218).

Claims: A method of establishing a call in an intelligent network (e.g., 20) comprising a plurality of telecommunication switching systems (e.g., 1,2) and data base systems (e.g., 11, 12, ..., 13), said switching systems and data base systems being interconnected by a signalling network (e.g., 10), the method comprising the step of: sending a query (e.g., 200), for data establishing said call, from one of said switching systems to a first one of said data base systems; and CHARACTERISED IN THAT the method further comprises the steps of: in said first data base system, determining whether said first data base system has enough data for responding to said query (e.g., 202); responsive to said first data base system determining that it does not have enough data to respond to said query, said first data base system sending a second query through the signalling network to a second one of said data base systems (e.g., 206); said second data base system finding data for responding to said second query and transmitting a response message directly to said switching system (e.g., 208); and said switching system using said data in said response message for establishing said call. A data base arrangement (e.g., 11, 12, ..., 13) for use in an intelligent network (e.g., 20) comprising a plurality of telecommunication switching systems (e.g., 1, 2) said switching systems and data base system being interconnected by a signalling network (e.g., 10), the data base arrangement comprising at least first and second data base systems, each provided with: means for receiving data (e.g., 32) from said signalling network; and means for transmitting data (e.g., 33) to said signalling network CHARACTERIZED IN THAT the first data base system further comprises processor means (e.g., 30), operative under the control of a program (e.g., 31) and responsive to a query message received by said means for receiving, for determining whether said first data base system has enough data (e.g., 35) for responding to said query, and if said first data base system does not have enough data to respond to said query, for controlling the transmitting by said means for transmitting of a second query over said signalling network, to the second data base system which is arranged to find data and transmit a response message comprising said found data for responding to said second query directly to said switching system.

Inventors: AHMAD NISAR, AHMAD, NISAR
Applicants: AT & T CORP, AT&T CORP.
Application year: 1993
Main classification: H04Q3
IPC codes: H04M3, H04L13, H04Q11, H04Q3