SYSTEM AND METHOD FOR COMMON INTELLIGENT NETWORK INTERCONNECTION
BACKGROUND OF THE INVENTION
Technical Field of the Invention
The present invention relates to the communications field and, in particular, to a system and method for interconnecting disparate networks and providing a common service layer.
Description of Related Art
Intelligent network (IN) applications have become one of the most important developments of the last decade in telephony, both wireless and wireline, adding significant value to service provider's consumer features and enhanced utility of the services provided. Advanced Intelligent networking (AIN) systems is a standard developed in the mid-1980 ' s to facilitate database accessing to route calls and provide various enhanced IN services. A more recent development, WIN, is another proposed solution to provide the increasingly enhanced telephone services demanded by
consumers, e.g., call forwarding, routing based on time of day or other parameters, etc.
As is understood in the art, the IN model separates call control signaling and voice. In particular, the switching system originating the invocation of the advanced service request maintains the voice portion of the call and requests the assistance of a centralized database, e.g., a Service Control Point (SCP) . The SCP contains various call processing data and associates service logic necessary to perform the requested advanced call services. One advantage of this division of labor approach is that, since the actual call remains at the switching point while only the call control data is transported over a separate data network to the SCP for call processing, the restrictions on transporting voice data across regulated boundaries is circumvented, as discussed in more detail hereinbelow.
To access service control, a Service Switching Point (SSP) analyzes the information associated with a call. As is understood in the art, this analysis occurs in multiple stages and at predetermined points during call processing in the SSP. Local switch provisioning is utilized to specify the call criteria needed to
trigger or invoke a request for SCP call processing at each predefined point. The SSP is programmed to selectively invoke the aid of service control at the SCP- triggered detection point (s) . It should also be understood that the SCP may require additional information from either the SSP or from the calling or called party. In these situations, information returned from the SCP can arm triggers occurring at subsequent points in call processing. The SCP can also request that the SSP prompt the user and collect additional information in the form of dialed digits .
It should also be understood that interactions with an intelligent peripheral (IP), e.g., a logically integrated remote adjunct machine, may be requested by the SCP in certain situations involving sophisticated user interaction. In such situations, since the SSP contains limited resources to process a voice- interaction portion of a call, the call is transferred to an IP using trunking. The SSP continues to manage the call, forming a gateway between the SCP and the IP. Upon completion of call handling by the IP, the SSP retrieves the call and continues call processing until final call disposition, e.g., as determined by SCP- resident service logic or SSP default processing rules.
As is understood in the art, a given IP itself contains limited service logic and data, usually only that required to locally perform the requests of the SCP. The data in an IP, for example, is generally specific to the user, such as voice samples, customized announcements and personal interactive data, which is too voluminous to maintain and download from the SCP on a per call basis. This data dependency distributes subscriber profile data for given service (s) across the SCP and the various IPs, and requires coordination between the SCP and the respective IPs in order to provide seamless service (s).
Another approach used to provide advanced call services and caller service interaction is to deploy a service node to implement this functionality. The service node model also employs a centralized device containing call processing data, service logic and audible voice or tones, along with optional digit or voice recognition circuitry. The service node may also include a switching mechanism to route calls to resources or to bridge multiple call "legs" for conference calling applications. As is understood in the art, the service node is deployed hierarchically and supports one or more switching systems . To access
these service nodes, inter-machine trunks (IMTs) from the respective associated switching office are employed, e.g., Tl or El type voice grade circuitry. It should be understood that while the service node is engaged in particular advanced call processing capabilities, the IMT trunks associated therewith are allocated for the duration of the call. Further, the service node itself appears to network switching systems as the next routing destination of the call, typically a tandem or inter-exchange carrier switching office, which does not directly support customer premise equipment and their associated network and traffic interfaces. If the service node requires subsequent routing of the call due to call processing, an additional IMT trunk is required to carry the outgoing portion of the call. The service node is then responsible for bridging the incoming and outgoing legs of the call .
When advanced call processing actions are completed, the call will either be held in the service node for the duration of the call or proprietary capabilities can be used to release the trunk back to the originating switching office. This action removes the service node from the call and releases all trunks
associated with the service node. At the time of the release back to the initiating switching system, a request is made to bridge the two ' legs ' of the call locally within the originating switching system. In some cases for geographic connectivity or cost reasons, a hubbing switch is used to access to the service node. This hub effectively tandems the voice traffic for the duration of the call and cannot be released. With reference now to FIGURE 1 of the drawings, there is illustrated a conventional service node architecture as described above and generally designated by the reference numeral 100, in which a management system node 110 is in communication with a number of discrete service nodes 120. A number of access layer nodes 130, such as an end office or an SSP, communicate with corresponding service nodes 120 via an Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) , and also communicate with SCP networks 140, e.g., a Signaling System 7 (SS7) protocol. As shown in FIGURE 1, one access layer node 130 may also provide the linkage between subordinate nodes 130A and 130B and a given service node 120.
The shortcomings of the aforedescribed IN and service node approaches, as generally illustrated in FIGURE 1, are many. Clearly, the operation and administration of multiple intelligent agents within a given network configuration is a costly, labor intensive and time consuming endeavor. With the addition of more and more applications to this type of platform, the overall complexity increases markedly, and the reliability and cost effectiveness of the infrastructure decreases.
Another difficulty is that the nature of regionally deployed IP's restricts access to an IP's data by the same services in other geographic regions. For example, a user's voice activated dialing service is only operational within a given IP's limited geographic region since the user's dialing directory is only accessible within that IP.
As discussed hereinbefore, due to numerous regulations by various legislative bodies, federal, state and international, incumbent carriers are forced to deploy network configurations driven by these arbitrary geographical boundaries . Additional barriers are imposed by service coverage area differences between disparate networks further complicating
deployment requirements. The costs of trunking and barriers created by these legislative boundaries prevent utilization of an overall centralized network which could decrease the aforementioned complexity and cost while increasing reliability.
Since an SSP must remain in control of a call, acting as a gateway for SCP-to-IP interactions, interaction with an intelligent peripheral for advanced call interactions consumes valuable SSP resources and processing capacity. It is also understood that in present systems intelligent peripherals must be deployed in a distributed network configuration and located close to the switching systems to which they are subtended, which, of course, is opposite to a centralized SCP architecture model, thereby counteracting the benefits provided by a centralized intelligent element approach.
A still further difficulty is that alternative voice bearing networks, such as IP Telephony (IPT), have no direct access to systems or data for mass services, such as Local Number Portability (LNP) , Calling Name Delivery and Toll Free. The IPT network does not support the trigger mechanism of a standard telephony network and must, therefore, rely on
different, proprietary access methods to provide enhanced services .
Finally, although certain announcements are often required within intelligent network services and as integral functions of a switching system, at present there is no solution for truly centralizing announcement management and the actual announcement messages. Instead, all announcements must be distributed to all SSPs and IPs, increasing the degree of data distribution, most of which is wasteful, adding cost and complexity to deploying services which will subsequently require announcement updating.
It is, therefore, an object of the present invention to provide an improved system and method for the interconnection of disparate networks which overcomes or minimizes the aforedescribed difficulties inherent in existing systems.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for providing a common intelligent network interconnection for transparently linking disparate networks using an emulation of customer equipment interfaces and alternate transport mechanisms, such as
Voice over Internet Protocol or other, packet-based transports .
BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the method and apparatus of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein : FIGURE 1 illustrates a conventional service node architecture ;
FIGURE 2 illustrates a telecommunications network for providing intelligent network interconnection in accordance with a first, logical embodiment of the present invention employing a packet-based transport mechanism, such as Voice over Internet Protocol;
FIGURE 3 illustrates a telecommunications network for providing intelligent network interconnection in accordance with a second, physical embodiment of the present invention employing a virtual loop around trunk transport mechanism;
FIGURE 4 illustrates a telecommunications network for providing intelligent network interconnection in accordance with a third, alternate physical embodiment
of the present invention employing a packet-switching mechanism, such as Asynchronous Transfer Mode or Frame Relay networking; and
FIGURE 5 illustrates a common service layer architecture for handling disparate voice-bearing networks in accordance with usage of any number of the embodiments of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be through and complete, and will fully convey the scope of the invention to those skilled in the art. With reference now to FIGURE 2, there is illustrated a common intelligent network interconnection, generally designated in the figure by the reference numeral 200, in accordance with a first and logical embodiment of the present invention. As
shown in FIGURE 2, Service Node/Intelligent Peripherals (SN/IPs) 210 are interconnected to a number of Internet Protocol Telephony (IPT) transport elements via Voice over IP (VoIP) , where the Internet connection is generally designated by the reference numeral 220. It should be understood, however, that the SN/IPs may constitute an intelligent call processing server or similar intelligent agent, as is known to those skilled in the art. The IPT transport elements in the present invention are used to define points of presence (POPs) , which provide switching office connectivity to one or more of the centralized intelligent agents 210. As discussed hereinbefore, these intelligent agent systems 210 may house various applications therein, e.g., service logic for call routing and handling services, announcement centers, voice response services, cashless calling card services or other call control mechanisms .
With reference again to FIGURE 2, communications between the intelligent agents 210 and the Internet 220 is facilitated by a respective VoIP gateway 215, e.g., an H.323 gateway or a Signaling System 7 (SS7) gateway, as are well understood to those skilled in the art. The interconnection between the intelligent agents 210
and the gateways 215 may utilize ISDN Primary Rate Interface (PRI) or Basic Rate Interface (BRI) trunking, and the interconnection between the gateways 215 and the Internet 220 is accomplished via Transmission Control Protocol/Internet Protocol (TCP/IP) .
A number of IPT transport elements, generally designated by the reference numeral 230, are connected to the Internet 220 via respective IPT gateways 225, e.g., using the aforementioned PRI trunking. With reference again to FIGURE 2, the respective IPT transport elements 230 may include an end office, an SSP, a Mobile Services Switching Center (MSC) , and any IP-Telephony device, which are all preferably interconnected via TCP/IP links. As is understood in the art, the IPT transport elements 230 may be connected to a Service Transfer Protocol (STP) network 240 and SCPs 250 via SS7 links, e.g., using a Tl trunk. Finally, a Service Management System (SMS) 260 provides communication between the aforedescribed intelligent agents 210 and the SCPs 250 via X.25 or integrated network management (INM) linkages.
Although SN/IPs have been utilized for intelligent telecommunications services, current SN/IP networks require end-to-end Tl or PRI connectivity using
standard voice transport trunks as the transport medium. As discussed, this approach is non-optimal and is fraught with problems. Through use of VoIP as the transport mechanism, however, as set forth in this first embodiment of the present invention, the interface between the switching system and the SN/IP network (s) is made more uniform and performance dramatically improved. In particular, the Internet Protocol (IP) connections may now be configured to operate within a dedicated intranet, e.g., using a switch-based transport backbone, or over the public Internet 220 depending upon the desired Quality of Service (QoS) level. By virtue of the improved configuration of the present invention, the network is configured to make each POP appear as Customer Premise Equipment (CPE) to voice-bearing networks using ISDN or SS7 Tl connectivity. It should be understood that this allows traditional CPE billing arrangements to apply. With this network configuration, the voice-bearing networks appear as standard SS7 Public Switched Telephone Network (PSTN) connections from the perspective of the IPT gateways 225, forming a virtual interface that allows the various IPT elements 230 within each voice-bearing network to effectively
perceive the intelligent agent 210 as a direct, CPE connection.
With reference now to FIGURE 3, there is illustrated another embodiment of the present invention in which instead of the VoIP as a transport medium, a loop-around-trunk transport methodology is employed, and generally designated in the figure by the reference numeral 300. As with the VoIP embodiment shown in FIGURE 2, an intelligent agent 310, such as an SN/IP, is connected to a gateway 315, such as the aforementioned VoIP gateway 215 of FIGURE 2. The gateway 315 is, in turn, connected to a Gateway Routing Center (GRC) 320 via a router 318 which establishes a Tl or ISDN link between the gateway 315 and GRC 320. Additionally, the router 318 can provide for diverse routing and deployment of native and M+l intelligent agents, as is understood to those skilled. The GRC 320 is connected to a number of IPT transport elements 330 again across Tl or other trunking links. The IPT elements 330 are in communication, e.g., using a PRI router 328, to IPT gateways 325, which interact with the GRC 320 via the high-speed, loop-around connection through the router 328 using, for example, TCP/IP transport. The transport elements 330 in this
embodiment include an end office and an SSP, which are preferably linked to an STP network 340 and an SCP 350 via SS7 links. The transport elements 330 may also be interconnected to each other via TCP/IP links. Similarly, with reference now to FIGURE 4, an
Asynchronous Transfer Mode (ATM) or Frame Relay Transport (FRT) methodology may be employed to provide the backbone transport medium, illustrating a further embodiment of the present invention, generally designated in the figure by the reference numeral 400. As with the previous embodiments set forth in FIGURES 2 and 3 and the associated text, an intelligent agent 410, such as an SN/IP, is connected to a gateway 415, such as the aforementioned VoIP gateway 215 of Figure 2. The gateway 415 is, in turn, connected to an ATM/FRT network 420 via a router 418 which established a Tl or ISDN link between the gateway 415 and network 420. The ATM/FRT network 420 is connected to a number of IPT gateways 425, again across Tl or other trunking lines, via a router 428. The IPT gateways are, in turn, connected to respective transport elements 430 via, for example, PRI trunks. The transport elements 430, e.g., an end office or SSP, are then linked to an STP network 440 and an SCP 450 via SS7 links. Finally, the
transport elements 430, as with the elements 330 in connection with FIGURE 3, may also be interconnected to each other via TCP/IP links.
It should be understood that to accomplish the aforedescribed interconnections, such as illustrated in FIGURES 3 and 4, the IPT networks connect to the voice- bearing networks Tl or ISDN at the bridging switch or the point in the switching path that advanced call processing is required. The IPT network then connects to the intelligent agent using, for example, SS7 and ANSI ISUP Tl trunks. At the local switching end, the IPT network maps the ISDN control channel (D-channel) or Tl SS7 control information into an SS7 superset. The ISDN feature activation messages are then converted to the appropriate SS7 ISUP control parameters and associated ISDN B channels are packetized using H.323 protocol. The voice and signaling data is then transported purely as data from the point of origination to termination. At the intelligent agent, the IPT gateway maps the H.323 messages into ANSI Tl parameters and directs the appropriate SS& signaling controls back to the intelligent agent. The reverse of the above process is performed for return traffic from the intelligent agent.
By virtue of the improved configuration of the present invention, SS7 signaling concepts are employed to seamlessly integrate switch-grade intelligent agents into disparate voice-bearing networks, providing universal, generic access across a variety of platforms. One advantage of this configuration is that since IPT and other packet-switching techniques allow call control to be cost-effectively handled over greater distances than traditional trunk technology. Using this improved configuration and methodology, call control platforms like intelligent agents can be centrally deployed. This centralization reduces the overall number of network resources required, and significantly reduces costs and labor associated with operations, administration and maintenance (OMP) .
Reduced Integrated Services Digital Network User Part
(ISUP) call transport and unlimited distance propagation allow adjunct call control elements, e.g., pre-paid calling, messaging, announcements, etc., to exist virtually anywhere in the network. Further, the IPT architecture effectively removes limitations due to the aforementioned legislative boundaries.
Through utilization of the improved system and method of the present invention, almost any voice-
bearing network can utilize the centralized intelligence by merely routing voice traffic to a dedicated trunk connected to the IPT gateway for transport to the intelligent network layer. For example, using the principles of the present invention, an embedded or legacy wireless IN network may be exploited by enacting routing to an SN/IP in order to perform call control for IPT networks. Additionally, wireless IN services may be provided using an embedded wireline IN network. Finally, multiple voice-bearing networks may be serviced using a single IN network.
Another advantage in implementing the methodology of the present invention is cost savings. As is known in the art, IPT elements inherently cost less than traditional trunk oriented connectivity components, such as ISDN PRI. By limiting PRI interfaces to on- site connections, substantial savings are realized. Since traditional ISDN and Tl trunks are also distance limited, further savings are realized by removing the need for signal repeaters, external echo cancelers, and other trunk conditioning equipment.
Used in conjunction with release link trunk (RLT) technology, calls within voice-bearing networks requiring advanced call processing by an intelligent
agent can be serviced and routed within the IPT network. Since voice and digit collection information travels uni-directionally during typical call control modes, sound quality remains high due to the absence of perceived delay created by bi-directional communication. Once advanced call processing is completed, the RLT function is exerted, the intelligent agent is removed from the call path, and all call parties are connected over high quality conventional trunks within the respective voice bearing networks. The release link capability provides the intelligent agent the ability to signal via ISUP messages to the "bridging switch" within the voice bearing network for call leg control. The intelligent agent can request the voice-bearing switch initiate new call attempts and locally bridge call legs, both the initial leg and subsequent follow-on calls at the bridging switch. Finally, the intelligent agent can request the bridging switch drop the intelligent agent itself (and subsequently the IPT transport network) and regain the call leg control of the calling and called parties. This is accomplished by using advanced network call management and conferencing features supported by BRI and PRI ISDN signaling.
Due to the expense of deploying numerous intelligent agents within voice-bearing networks, a technique called "switch hubbing" is typically used to reduce the number of agents required. The hubbing switch provides connectivity into an intelligent agent for multiple switching centers . This technique reduces the need to deploy intelligent agents for each site. However, inter-office trunks between the hubbing switch and the switches it serves are occupied for the entire duration of the call. This active role consumes valuable trunk resources and processor capacity, significantly impacting the capacity of the hubbing switch to process its own calls. Additionally, voice traffic handled in this manner is restricted to Local Access Transport Area (LATA) in the United States due to FCC regulations. Similar transborder restrictions are imposed in other parts of the world due to country borders, commerce agreements, or other regulatory controls . The system and method of the present invention removes each of these limitations since no hubbing switch is required. In addition, LATA or other transborder boundary regulations are not breached since the actual call is ultimately connected between the
calling and the called party switches. Only call control information passes across the LATA boundary. Even inter-exchange calls requiring inter-LATA transport are handled seamlessly since normal call setup is invoked by the RLT function as the final stage of call processing. Finally, should it become desirable to allow calls to transpire over the IPT network, LATA encroachment remains intact since voice is data in a packet-switched transport network. (While the LATA concept is unique to North America, other boundaries for voice traffic in international applications can also be overcome in similar fashion) .
In traditional ISUP trunk networks, automated announcements, and digitized voice interaction normally incur slight delays during call processing and digit reception. These operations can be improved by the additional bandwidth supplied when using an IP interconnect network. This can be accomplished by altering the QoS parameters of the IP transport medium to the desired service level.
It should be understood that the aforementioned Points of Presence or POPs are preferably interfaced to the switching offices via an inter-exchange Tl or local CPE, such as ISDN BRI and PRI, where the choice between
Tl and ISDN is made depending upon the type of service required. For traditional IN-type services, the trunking Tl interface is preferably used. For advanced call leg management services, it should be understood that ISDN is preferred. By interfacing the POPs directly at the particular switching systems to which the customers are actually connected, it is possible to the provide intelligent network services that normally require expensive and complex call model switching system software.
Another illustration of the resultant network architecture envisioned through use of the principles of the present invention is shown in FIGURE 5. In particular, the network, designated for convenience by the reference numeral 500, presents a common service layer for handling disparate voice-bearing networks, as described in some detail hereinabove. The hierarchically-arranged model shown in FIGURE 5 has various layers. For example, at an access layer, generally designated by the reference numeral 510, users may access the disparate voice-bearing networks, e.g., a network 515, shown dispersed on the level planes 520A and 520B.
As additionally shown in FIGURE 5, the various networks 515 arrayed on plane or layer 520B interact with an inter-exchange switching layer 525, upon which control nodes 530, such as SCPs, reside to handle the user connections to the higher layer (s) . The layers 520A and 525 are, in turn, connected to a service and data layer 530 upon which additional control nodes 535 are arrayed within respective grouping planes 540A, 540B, 540C and 540D. As shown in the figure, the respective control nodes 535 at the service and data layer 530 are in communication with one or more service management nodes 545 upon a service delivery layer 550. As illustrated, the nodes 545 are, in turn, interconnected also. The commonality of the service layer architecture, across a variety of distinct and disparate voice- bearing networks, present the user with a uniform CPE interface with which to utilize the numerous intelligent network functionality present in current systems and yet to come.
Although preferred embodiments of the system and method of the present invention has been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it should be understood
that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.