CROSS-REFERENCE TO RELATED APPLICATIONS 
   This is an application claiming the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/687,364 entitled “REDUNDANCY MECHANISMS IN A PUSH-TO-TALK REALTIME CELLULAR NETWORK” which was filed Jun. 3, 2005. The entirety of which is incorporated by reference herein. 


   BACKGROUND OF THE INVENTION 
   Walkie-talkies are far and away the most convenient type of radio communications system for a quick exchange of information. A user pushes the button and is in instant communication with one or a whole group of contacts. Due to the speed and convenience of this technology, telecommunications carriers have incorporated this technology into cellular technology for use with mobile handsets. 
   Accordingly, push-to-talk (PTT) is a two-way communications method integrated into cellular technology that uses half-duplex mode where transmission occurs in both directions, but not at the same time. To use PTT, users must press a button on the PTT device while speaking, then release it when done. The listener must then do the same to respond. A typical PTT session can last about 20 to 30 seconds, versus roughly 3 minutes for a traditional cellular call. 
   However, the integration of PTT technology and cellular technology has not been seamless. Among other issues, telecommunications carriers have been plagued with reliability and efficiency concerns due to the integration of the PTT and cellular technology. Reliability of PTT technology has been addressed in a variety of ways, but to date, very few telecommunications carriers provide a reliable and efficient PTT service for their cellular networks. Typically, the PTT technology can be constructed with internal redundancy, however, the PTT technology does not have a provision for geographic or realtime mated redundancy. 
   Accordingly, there exists a demand for improved reliability and efficiency, such as geographic or realtime mated redundancy, for PTT service on cellular networks. 
   SUMMARY 
   The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed innovation. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
   The subject innovation facilitates a redundant core delivery system for the emulation of “walkie-talkie” (or push-to-talk (PTT)) service with circuit switched duplex calls in a circuit-switched carrier network. The disclosed architecture provides for geographic and/or realtime mated redundancy. In one implementation, realtime redundancy is offered in an active-active scenario, although other scenarios are possible. This maintains the existing hardware footprint and reduces the footprint from a proposed convention N+1 configuration. Conventionally, in this one example, three active hardware components are implemented with one non-traffic bearing (or standby) unit. 
   The subject innovation provides, in an active-active scenario, the same four chassis, but in two mated and redundant configurations. Since all four units can now have an identical chassis configuration, they can also all be traffic-bearing units. Accordingly, if either of the pair member units fails to function, then all originated calls will continue to be handled in the network by the geographically diverse mate unit. At the time of recovery of the failed mated unit, a database associated with the failed unit now being brought back online, can be utilized to update from the live (active) database of the operational mate. The mated unit will receive updates for new customers from its mate concurrent with all other updates to the database. Thus, a record can be made instantly available at the mate during event failure scenarios in the network. 
   In order for two units to act in a mated active-active configuration, an interconnection is provided to facilitate communication therebetween to ensure that hosted subscriber databases are kept in synchronization with one another. Additionally, this communication interconnection can use the same realtime communications as the link provided in a conventional N+1 configuration, thereby reducing or eliminating entirely any need by technicians to physically reconfigure the existing systems. 
   A core memory level of the pair units will be sufficiently substantial to maintain 100% of the subscriber base. If needed, an additional memory card can be inserted into the existing single chassis to expand its memory capacity. 
   The traffic distribution between the mated pair systems can be distributed by both a STP (signal transfer point) and the originating MSC (mobile switching center), or either unit individually. This can also push the availability for the platform beyond the 99.998% level. 
   Provisioning for the active-active mated pair can be identical to the current provisioning scheme utilizing an EMS (element management system). The EMS can also run in a configuration that allows for provisioning to the mated units so as to maintain customer convenience. 
   In another aspect thereof, redundancy is provided in a roaming gateway implementation of the PTT network. 
   In yet another aspect thereof, an artificial intelligence component is provided that employs a probabilistic and/or statistical-based analysis to prognose or infer an action that a user desires to be automatically performed. 
   To the accomplishment of the foregoing and related ends, certain illustrative aspects of the disclosed innovation are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles disclosed herein can be employed and is intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a system of redundant packet core delivery subsystems in accordance with the subject innovation. 
       FIG. 2  illustrates a methodology of providing redundancy in realtime voice delivery system according to an aspect. 
       FIG. 3  illustrates a methodology of synchronizing databases in a failure mode in accordance with another aspect. 
       FIG. 4  illustrates a methodology of provisioning in accordance with another aspect of the innovation. 
       FIG. 5  illustrates a schematic block diagram of a system of mated pair of packet core delivery systems. 
       FIG. 6  illustrates a system of redundant roaming gateways in accordance with the disclosed innovation. 
       FIG. 7  illustrates a network that employs packet core delivery system redundancy in another aspect. 
       FIG. 8  illustrates a redundant packet core delivery system that employs an artificial intelligence which facilitates automating one or more features in accordance with the subject innovation. 
       FIG. 9  illustrates an active-active configuration that utilizes two STP pairs according to an aspect. 
       FIG. 10  illustrates an active-active configuration that utilizes a single STP pair according to an aspect. 
       FIG. 11  illustrates an active-active configuration that utilizes two STP pairs and corresponding tandem switches for interfacing voice traffic to corresponding redundant mated pairs according to an aspect. 
       FIG. 12  illustrates an active-active configuration that utilizes a single STP pair and corresponding tandem switches for interfacing voice traffic to corresponding redundant mated pairs according to an aspect. 
   


   DETAILED DESCRIPTION 
   The innovation is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the innovation can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate a description thereof. 
   As used in this application, the terms “component” and “system” are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, a hard disk drive, a cellular network hardware or software entity (e.g., a switch or a router), multiple storage drives (of optical and/or magnetic storage medium), an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers. 
   As used herein, the term to “infer” or “inference” refer generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic—that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources. 
   Referring initially to the drawings,  FIG. 1  illustrates a system  100  of redundant core delivery systems in accordance with the subject innovation. Conventionally in IP-centric networks, such systems employ an N+1 configuration, where there can be, for example, three active units, and a fourth standby (passive or non-traffic bearing) unit, that is readily available for use in case one of the first three units goes offline due to failure or other problems. Whereas, in accordance with the invention, there are provided mated pairs of redundant core delivery systems configured in an active-active configuration. In other words, there is not a single standby unit for the other traffic-bearing units. A mated pair comprises two fully operational traffic-bearing units connected to provide full synchronization of the onboard subscriber database. 
   Since all four units are traffic bearing, each can have an identical single chassis configuration. In order for the units to act in a mated active-active configuration, the mated pair communicates in order to ensure the subscriber database is kept in synchronization. This communication uses the identical near realtime communications interface as provided in an N+1 configuration. It is to be understood that more units can be implemented according to the needs of the particular application. 
   Additionally, the core memory level of the mated pair is substantially sufficient to maintain 100% of the subscriber base. If needed, an additional memory card (not shown) can be inserted into the existing pair member unit to expand its memory capacity. 
   The traffic distribution between the pair can be distributed by both a signal transfer point (STP) and the originating mobile switching center (MSC), or either unit individually. This can also push the availability for the platform beyond the 99.998% level. Accordingly, if either of the pair member units fails to function while in the active-active configuration, all originated calls will continue to be handled in the network by the geographically diverse mate unit. 
   Here, there are provided two mated pairs of units in an active-active configuration. A first mated pair  102  includes a first core delivery system (denoted CDS 1 -A) and a second core delivery system (denoted CDS 1 -B), each hosting the same first subscriber database  104 . Similarly, the system  100  includes a second mated pair  106  having a first core delivery system (denoted CDS 2 -A) and a second core delivery system (denoted CDS 2 -B), each hosting the same subscriber database  108 , but which can be different from the first subscriber database  104 . Alternately, both mated pairs ( 102  and  106 ) can host the same subscriber database, such that if one mated unit fails, voice traffic is not interrupted, since the second mated unit is fully operational and with the same subscriber data as the first mated unit. The core delivery systems can handle IP packets, non-IP based data, or both. 
   Further, the first mated pair  102  is interconnected via a first pair connection  110 , and the second mated pair  106  is interconnected via a second pair connection  112 . The interconnections ( 110  and  112 ) can be IP data connections or any other connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. Generally, the interconnections ( 110  and  112 ) facilitate redundancy communications between each mated pair. 
   In this implementation, the environment in which the system  100  is employed carries non-packet realtime telecommunications voice traffic, where guaranteed signal delivery is required. In operation, if the first member unit CDS 1 -A goes offline to signaling but does not fail its voice connections, voice traffic is not interrupted, since the second member unit CDS 1 -B is fully operational and with the same subscriber data (via synchronization) as the first member unit CDS 1 -A, all new originating calls are handled without interruption. The second member unit CDS 1 -B operates and updates its database. When the first member unit CDS 1 -A comes back online, the first and second units  102  initialize communications between each other, and prior to handling traffic, will perform database synchronization. That is, the first unit CDS 1 -A updates its database  104  from the database  104  of the second unit CDS 1 -B. Once fully synchronized, the first unit CDS 1 -A is then placed back into full service. It is also to be appreciated that these units can be geographically diverse. That is, the first member unit CDS 1 -A can be deployed in another city or state from the second member unit CDS 1 -B. 
   As illustrated in  FIG. 1 , the first mated pair  102  interfaces to a mated pair of STP units  114  which operate according to the SS7 (Signaling System 7) signaling architecture (e.g., Telcordia standards GR-246-CORE and GR-82-CORE for ANSI networks). An STP is a packet switch, and is the signaling router in the SS7 network. It transfers messages that use the same national standard of protocol (e.g., Telcordia GR-246-CORE for ANSI networks, Q.703 and Q.704 for ITU networks). Similarly, the second mated pair  106  interfaces to a mated pair of STP units  116  which operate according to the SS7 signaling architecture. Accordingly, the first mated pair  102  interfaces to the second mated pair  106  via two mated pairs of STP units ( 114  and  116 ) which operate according to SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 102  and  106 ). 
     FIG. 2  illustrates a methodology of providing redundancy in realtime voice delivery system according to an aspect. While, for purposes of simplicity of explanation, the one or more methodologies shown herein, e.g., in the form of a flow chart or flow diagram, are shown and described as a series of acts, it is to be understood and appreciated that the subject innovation is not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with the innovation. 
   At  200 , a pair of redundant core delivery systems is provided. The pair of redundant core delivery systems each hosts at least one subscriber database. As both units share a synchronization link, the redundant core delivery systems will have identical subscriber data. At  202 , the two units are interfaced and configured as active-active traffic-bearing units. It is noted that the subject innovation is not limited to active-active applications, but can be implemented in other environments such as active-passive, passive-active, active-passive-passive, active-active-passive, and so on. At  204 , once operationally interfaced, the mated pair synchronizes subscriber databases. This can occur on a regular basis, for example, as each unit updates it own database, it sends data to the other. It is to be appreciated however; the units can synchronize databases on a periodic basis, and/or at times when network traffic is not so busy, for example. 
   Referring now to  FIG. 3 , there is illustrated a methodology of synchronizing databases in a failure mode in accordance with another aspect. At  300 , a pair of redundant core delivery systems is received for implementation. As stated supra, the pair of redundant core delivery systems each hosts at least one subscriber database. At  302 , the units are interfaced to each other and configured, in one implementation, as active-active units. At  304 , initial database synchronization can occur, although this is not required. As both units share a synchronization link, the redundant core delivery systems will have identical subscriber data within each subscriber database. At  306 , the system operates normally. At  308 , the system checks for unit failures. If no failure is detected, flow is back to  306  wherein the system continues to operate normally and continues to perform system checks for unit failures. 
   If a failure has been detected, flow is from  308  to  310  (or  318  to  320 ) where the second member unit of the redundant core delivery systems takes over for the failed unit. This includes processing the traffic of the failed unit, in addition to its own traffic. At  312  (or  322 ), the system checks to determine if the failed unit is back online or another operational unit is operationally available (via replacement or repair, for example). If not, flow loops back to  312  (or  322 ) wherein the system continues to operate without the failed unit and continues to perform system checks to determine if the failed unit is back online. If the failed unit is back online via replacement or repair, etc., at  314 , the newly operational unit synchronizes its database with the operational member unit. Once fully synchronized, at  316 , the new unit is placed back into service and its load is offloaded from the other member unit to the new unit, thereby preventing loss or interruption of voice traffic. 
     FIG. 4  illustrates a methodology of provisioning in accordance with another aspect of the innovation. At  400 , a pair of redundant core delivery systems is provided. As stated supra, the pair of redundant core delivery systems each hosts at least one subscriber database. At  402 , the two units are interfaced and configured as active-active traffic-bearing units. At  404 , once operationally interfaced, the mated pair synchronizes subscriber databases. As both units share a synchronization link, the redundant core delivery systems will have identical subscriber data within each subscriber database. At  406 , both mated units are provisioned. Generally, provisioning for the active-active mated pair can be identical to the current provisioning scheme utilizing an EMS (element management system). The EMS can also run in a configuration that allows for provisioning to the mated units so as to maintain customer convenience. Further, at  408 , if one of the core delivery systems fails, the remaining operational unit will take over traffic processing for both units and will receive updates destined to both subscriber databases. At  410 , once the failed unit is back on-line (repaired), the mated pair synchronizes subscriber databases. At the time of recovery of the failed mate, the database would update from the live (active) database on the operational mate. The mated unit will receive updates for new customers from its mate, concurrent with all other updates to the database. Thus, provisioning of the active-active mated pair allows an instantly available record at the mate during event failure scenarios in the network. 
     FIG. 5  illustrates a schematic block diagram of a system  500  of a mated pair of core delivery systems. A first unit  502  is mated to a second unit  504  for redundant signal processing in an SS7 architecture. The first and second units ( 502  and  504 ) are interconnected via a communications connection  506  that supports at least failure detection of one unit or the other, and database synchronization of the associated subscriber databases. The first unit  502  can include a management component  508  that facilitates management of some or all processing of the first unit  502 . A synchronization component  510  that facilitates data synchronization of a first unit subscriber database  512 , such that the subscriber databases ( 512  and  522 ) contain the same subscriber data when both core delivery systems ( 502  and  504 ) are operational. A memory  514  (e.g., a cache memory) of the first unit  502  is provided for fast data processing, and for storing temporarily programs and/or data that is cached for high speed execution. The memory  514  is sized according to the anticipated traffic and according to synchronization needs, for example. A communications component  516  facilitates the interface to the STP entities for at least traffic routing and handling. Note that communications that can occur across the interconnection  506  can also be facilitated via the communications component  516 , as well as routing and handling that occurs to the STP units. 
   Similarly, the second unit  504  can include a management component  518  that facilitates management of some or all processing of the second unit  504 . A synchronization component  520  that facilitates data synchronization of the second unit subscriber database  522 , such that the subscriber databases ( 512  and  522 ) contain the same subscriber data when both core delivery systems ( 502  and  504 ) are operational. A memory  524  (e.g., a cache memory) of the second unit  504  is provided for fast data processing, and for storing temporarily programs and/or data that is cached for high speed execution. The memory  524  is sized according to the anticipated traffic and according to synchronization needs, for example. A communications component  526  facilitates the interface to the STP entities for at least routing and handling. 
   Referring now to  FIG. 6 , there is illustrated a system of redundant roaming gateways in accordance with the disclosed innovation. Similar to the redundancy of the core delivery systems described supra, the roaming gateways can be interconnected to provide true redundancy. Thus, there is provided a mated pair of roaming gateways  600  which are interconnected by a communications connection  602  to facilitate redundancy communications. The first pair member  606  can include a management component  608  that facilitates management of some or all processing of the first pair member  606 . Gateway tables  610  can be created for storing relationships of information. All information coming in to the gateway that references a desired connection to an outgoing network can be stored in the gateway table(s) as a record. Thus, owners of the gateway can monitor the gateway table(s) to see where the traffic is coming from and going. Accordingly, the gateway table(s) maps one incoming address to an outgoing address (i.e., address translation) between different networks. 
   Similarly, the second pair member  612  can include a management component  614  that facilitates management of some or all processing of the second pair member  612 . Gateway tables  616  can be included for storing relationships of information and thus, enabling owners of the gateway to monitor traffic between different networks. Furthermore, each of the pair members ( 606  and  612 ) connects redundantly to a mated pair of gateway STP devices  604  to facilitate redundancy in traffic distribution between the first and second mated pair members ( 606  and  612 ). 
     FIG. 7  illustrates a network  700  that employs core delivery system redundancy in another aspect. Here, there are provided two redundant sets of two mated pairs of units in an active-active configuration. In the first set  738 , a first mated pair  702  includes a first core delivery system (denoted CDS 1 -A) and a second core delivery system (denoted CDS 1 -B), each hosting the same first subscriber database  706  (denoted DBS 1 -A and DBS 1 -B). Similarly, the system  700  includes a second mated pair  708  having a first core delivery system (denoted CDS 2 -A) and a second core delivery system (denoted CDS 2 -B), each hosting the same subscriber database  712  (denoted DBS 2 -A and DBS 2 -B), but which is different from the first subscriber database  706 . The core delivery systems can handle IP packets, non-IP based data, or both. 
   Further, the first mated pair  702  is interconnected via a first pair connection  704 , and the second mated pair  708  is interconnected via a second pair connection  710 . The interconnections ( 704  and  710 ) can be IP data connections or any other connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. 
   In this implementation, the environment in which the system  700  is employed carries non-packet realtime telecommunications voice traffic, where guaranteed signal delivery is required. In operation, if the first member unit CDS 1 -A goes offline to signaling but does not fail its voice connections, voice traffic is not interrupted, since the second member unit CDS 1 -B is fully operational and with the same subscriber data (via synchronization) as the first member unit CDS 1 -A, all new origins are handled without interruption. The second member unit CDS 1 -B operates and updates its database. When the first member unit CDS 1 -A comes back online, the first and second units initialize communications between each other, and prior to handling traffic will perform database synchronization. That is, the first unit updates its database from the database of the second unit. Once fully synchronized, the first unit is then placed back into full service. It is also to be appreciated that these units are geographically diverse. That is, the first member unit CDS 1 -A can be deployed in another city or state from the second member unit CDS 1 -B. 
   As illustrated in  FIG. 7 , the first mated pair  702  of the first set  738  interfaces to a mated pair of STP units  714  which operate according to the SS7 (Signaling System 7) signaling architecture (Telcordia standards GR-246-CORE and GR-82-CORE for ANSI networks). The second mated pair  708  of the first set  738  interfaces to a separate mated pair of STP units  716  which operate according to the SS7 signaling architecture. Accordingly, the first mated pair  702  interfaces to the second mated pair  708  via two mated pairs of STP units ( 714  and  716 ) which operate according to SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 702  and  708 ) of the first set  738 . 
   Furthermore, the system  700  includes a second set  740  completely redundant to the first set  738 . The second set  740  includes a first mated pair  718  that includes a first core delivery system (denoted CDS 1 -A) and a second core delivery system (denoted CDS 1 -B), each hosting the same first subscriber database  706  (denoted DBS 1 -A and DBS 1 -B) as in the redundant first mated pair  702  of first set  738 . Similarly, the second set  740  includes a second mated pair  722  having a first core delivery system (denoted CDS 2 -A) and a second core delivery system (denoted CDS 2 -B), each hosting the same subscriber database  712  (denoted DBS 2 -A and DBS 2 -B) as in the redundant second mated pair  708  of first set  738 . Accordingly, both sets ( 738  and  740 ) are completely redundant and can host the same subscribe databases ( 706  and  712 ), such that if one complete mated unit (e.g.,  702 ) fails, voice traffic is not interrupted, since the second complete mated unit ( 718 ) is fully operational and with the same subscriber data as the first complete mated unit ( 702 ). 
   As further illustrated in  FIG. 7 , the first mated pair  718  of the second set  740  interfaces to a mated pair of STP units  726  which operate according to the SS7 signaling architecture. The second mated pair  722  of the second set  740  interfaces to a separate mated pair of STP units  728  which operate according to the SS7 signaling architecture. Accordingly, the first mated pair  718  interfaces to the second mated pair  722  via two mated pairs of STP units ( 726  and  728 ) which operate according to SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 718  and  722 ) of the second set  740 . 
   Additionally, the mated pairs of STP units ( 714  and  716 ;  726  and  728 ) interface with a mated pair of Gateway STP units  730 . The mated pair of Gateway STP units  730  interfaces with a pair of roaming gateways  732  to facilitate traffic distribution between different networks. Similar to the redundancy of the core delivery systems described supra, the roaming gateways can be interconnected to provide true redundancy. Thus, there is provided a pair of roaming gateways  732  which are interconnected by a communications connection  734  to facilitate redundancy communications. Gateway tables  736  (denoted GW-TABLE) can be included for storing relationships of information and thus, enabling owners of the gateway to monitor traffic between the different networks. Accordingly, the gateway table(s)  736  maps one incoming address to an outgoing address (i.e., address translation) between different networks. 
     FIG. 8  illustrates a mated pair system  800  that employs an artificial intelligence (AI) which facilitates automating one or more features in accordance with the subject innovation. Here, a first member unit  802  of the pair can include the components of  FIG. 5 : the management component  508 , the synchronization component  510 , the subscriber database  512 , the memory component  514 , and the communications component  516 . Additionally, the first unit  802  includes an AI component  804 . Similarly, the system  800  includes a second member unit  806 , which can include the following components of  FIG. 5 : the management component  518 , the synchronization component  520 , the subscriber database  522 , the memory component  524 , and the communications component  526 . Additionally, the second member unit  806  can include an AI component  808 . 
   The subject innovation (e.g., in connection with selection) can employ various AI-based schemes for carrying out various aspects thereof. For example, a process for determining when to perform database synchronization can be facilitated via an automatic classifier system and process. 
   A classifier is a function that maps an input attribute vector, x=(x 1 , x 2 , x 3 , x 4 , xn), to a confidence that the input belongs to a class, that is, f(x)=confidence(class). Such classification can employ a probabilistic and/or statistical-based analysis (e.g., factoring into the analysis utilities and costs) to prognose or infer an action that a user desires to be automatically performed. 
   A support vector machine (SVM) is an example of a classifier that can be employed. The SVM operates by finding a hypersurface in the space of possible inputs, which hypersurface attempts to split the triggering criteria from the non-triggering events. Intuitively, this makes the classification correct for testing data that is near, but not identical to training data. Other directed and undirected model classification approaches include, e.g., naïve Bayes, Bayesian networks, decision trees, neural networks, fuzzy logic models, and probabilistic classification models providing different patterns of independence can be employed. Classification as used herein also is inclusive of statistical regression that is utilized to develop models of priority. 
   As will be readily appreciated from the subject specification, the subject invention can employ classifiers that are explicitly trained (e.g., via a generic training data) as well as implicitly trained (e.g., via observing user behavior, receiving extrinsic information). For example, SVM&#39;s are configured via a learning or training phase within a classifier constructor and feature selection module. Thus, the classifier(s) can be employed to automatically learn and perform a number of functions, including but not limited to determining when to initiate database synchronization of a failed pair member that is now operational. Additionally, the AI component  802  can be employed to determine how long synchronization can take, and based on that information, when to perform synchronization. For example, if the traffic is heavy, is may be desirable to delay synchronization to a time when traffic is not so heavy. This can be learned based on historical data. If the traffic historically is less later at night, synchronization may be performed more often, while during heavy traffic times, it is performed less often. These are just a few examples of how the AI components ( 802  and  804 ) can be configured and employed. 
     FIG. 9  illustrates an active-active configuration that utilizes two mated STP pairs according to an aspect. In this configuration  900 , two sets of mated device pairs ( 902  and  904 ) are shown. The first mated pair  902  hosts the same first subscriber data  906 . As both units share a synchronization link  908 , the first mated pair  902  will have identical subscriber data. Similarly, the system  900  includes a second mated pair  904  that hosts the same second subscriber data  910 , but which is different from the first subscriber data  906 . As both units share a synchronization link  912 , the second mated pair  904  will have identical subscriber data. The synchronization links ( 908  and  912 ) can be IP data connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. 
   Further, the first mated pair  902  interfaces to a mated pair of STP units  914  which operate according to the SS7 signaling architecture. The second mated pair  904  interfaces to a separate mated pair of STP units  916  which operate according to the SS7 signaling architecture. Accordingly, the first mated pair  902  interfaces to the second mated pair  904  via two mated pairs of STP units ( 914  and  916 ) which operate according to SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 902  and  904 ). SS7 signaling between the mated pairs ( 902  and  904 ) is carried out by way of STP units  914  connecting to STP units  916 . Each of the STPs is, in actuality, a pair of STP units. This provides each STP installation with load-sharing and backup capabilities. Thus the links shown in  FIG. 9  as being connected to an STP are, in actuality, divided between the two STP units of an STP pair ( 914  and  916 ). The addition of two mated pairs of STP units ( 914  and  916 ) operates to more efficiently control traffic distribution between the first and second mated pairs ( 902  and  904 ) and provides additional redundancy and load-sharing capabilities as compared to just one mated pair of STP units. 
   In operation, the loss of one member of the mated pair  902  (going offline) will cause a reroute of services to the remaining member. Since both units share a synchronization link  908 , they will both have identical subscriber data  906 . The data  906  can be stored in high speed memory (e.g., volatile or non-volatile) and/or RAM drive or other suitable high-speed storage and access subsystem. The second member unit operates and updates its subscriber data  906 . When the first member unit comes back online, the first and second units initialize communications between each other, and prior to handling traffic will perform data synchronization. Note that in this configuration, only the loss of the mated pair (e.g.,  902  or  904 ) will result in loss of service. 
     FIG. 10  illustrates an active-active configuration that utilizes a single STP pair according to an aspect. In this configuration  1000 , two sets of mated device pairs ( 1002  and  1004 ) are shown. The first mated pair  1002  hosts the same first subscriber data  1006 . As both units share a synchronization link  1008 , the first mated pair  1002  will have identical subscriber data. Similarly, the system  1000  includes a second mated pair  1004  that hosts the same second subscriber data  1010 , but which is different from the first subscriber data  1006 . As both units share a synchronization link  1012 , the second mated pair  1004  will have identical subscriber data. The synchronization links ( 1008  and  1012 ) can be IP data connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. 
   Further, both the first and second mated pairs ( 1002  and  1004 ) interface to a mated pair of STP units  1014  which operate according to the SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 1002  and  1004 ). SS7 signaling between the mated pairs ( 1002  and  1004 ) is carried out by way of STP units  1014 , which is, in actuality, a pair of STP units. This provides each STP installation with load-sharing and backup capabilities. Thus, the links shown in  FIG. 10  as being connected to an STP are, in actuality, divided between the two STP units of an STP pair  1014 . Accordingly, it is also possible to use the active-active configuration with only a single pair of STP units  1014 , as opposed to the two pairs of STP units ( 914  and  916 ) illustrated in  FIG. 9 . 
   In operation, the loss of one member of the mated pair  1002  (going offline) will cause a reroute of services to the remaining member. Rerouting of services to the operational member due to a failure of the other mated member is automatic. Since both units share a synchronization link  1008 , they will both have identical subscriber data  1006 . The second member unit operates and updates its subscriber data  1006 . When the first member unit comes back online, the first and second units initialize communications between each other, and prior to handling traffic will perform data synchronization. Again, only the loss of a mated pair (e.g.,  1002  or  1004 ) will results in loss of service. In contrast, a conventional N+1 configuration to a single STP pair would require manual intervention of redirection to the inactive member unit. 
     FIG. 11  illustrates an active-active configuration that utilizes two STP pairs and tandem switches for interfacing voice traffic to the corresponding redundant mated pairs according to an aspect. In this configuration  1100 , two sets of mated device pairs ( 1102  and  1104 ) are shown. The first mated pair  1102  hosts the same first subscriber data  1106 . As both units share a synchronization link  1108 , the first mated pair  1102  will have identical subscriber data. Similarly, the system  1100  includes a second mated pair  1104  that hosts the same second subscriber data  1110 , but which is different from the first subscriber data  1106 . As both units share a synchronization link  1112 , the second mated pair  1104  will have identical subscriber data. The synchronization links ( 1108  and  1112 ) can be IP data connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. 
   In the configuration  1100 , the two sets of mated device pairs ( 1102  and  1104 ) interface with tandem switches ( 1118  and  1120 ). Specifically, the first mated pair  1102  interfaces with tandem switch  1118 , which in turn interfaces with the voice network  1122 . Tandem switch  1118  acts to route voice data to and from the voice network  1122  to the member units of the first mated pair  1102 . Similarly, the second mated pair  1104  interfaces with tandem switch  1120 , which in turn interfaces with the voice network  1122 . Tandem switch  1120  acts to route voice data to and from the voice network  1122  to the member units of the second mated pair  11104 . 
   Further, the first mated pair  1102  interfaces to a mated pair of STP units  1114  which operate according to the SS7 signaling architecture. The second mated pair  1104  interfaces to a separate mated pair of STP units  1116  which operate according to the SS7 signaling architecture. Accordingly, the first mated pair  1102  interfaces to the second mated pair  1104  via two mated pairs of STP units ( 1114  and  1116 ) which operate according to SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 1102  and  1104 ). SS7 signaling between the mated pairs ( 1102  and  1104 ) is carried out by way of STP units  1114  connecting to STP units  1116 . Each of the STPs is, in actuality, a pair of STP units. This provides each STP installation with load-sharing and backup capabilities. Thus the links shown in  FIG. 11  as being connected to an STP are, in actuality, divided between the two STP units of an STP pair ( 1114  and  1116 ). The addition of two mated pairs of STP units ( 1114  and  1116 ) operates to more efficiently control traffic distribution between the first and second mated pairs ( 1102  and  1104 ) and provides additional redundancy and load-sharing capabilities as compared to just one mated pair of STP units. 
   In operation, the loss of one member of the mated pair  1102  (going offline) will cause a reroute of services to the remaining member. Since both units share a synchronization link  1108 , they will both have identical subscriber data  1106 . The data  1106  can be stored in high speed memory (e.g., volatile or non-volatile) and/or RAM drive or other suitable high-speed storage and access subsystem. The second member unit operates and updates its subscriber data  1106 . When the first member unit comes back online, the first and second units initialize communications between each other, and prior to handling traffic will perform data synchronization. Note that in this configuration, only the loss of the mated pair (e.g.,  1102  or  1104 ) will result in loss of service. 
     FIG. 12  illustrates an active-active configuration that utilizes a single STP pair and tandem switches for interfacing voice traffic to the corresponding redundant mated pairs according to an aspect. In this configuration  1200 , two sets of mated device pairs ( 1202  and  1204 ) are shown. The first mated pair  1202  hosts the same first subscriber data  1206 . As both units share a synchronization link  1208 , the first mated pair  1202  will have identical subscriber data. Similarly, the system  1200  includes a second mated pair  1204  that hosts the same second subscriber data  1210 , but which is different from the first subscriber data  1206 . As both units share a synchronization link  1212 , the second mated pair  1204  will have identical subscriber data. The synchronization links ( 1208  and  1212 ) can be IP data connections that facilitate at least database synchronization between the pair member units and failure detection by one unit or the other. 
   In the configuration  1200 , the two sets of mated device pairs ( 1202  and  1204 ) interface with tandem switches ( 1216  and  1218 ). Specifically, the first mated pair  1202  interfaces with tandem switch  1216 , which in turn interfaces with the voice network  1220 . Tandem switch  1216  acts to route voice data to and from the voice network  1220  to the member units of the first mated pair  1202 . Similarly, the second mated pair  1204  interfaces with tandem switch  1218 , which in turn interfaces with the voice network  1220 . Tandem switch  1218  acts to route voice data to and from the voice network  1220  to the member units of the second mated pair  1204 . 
   Further, both the first and second mated pairs ( 1202  and  1204 ) interfaces to a mated pair of STP units  1214  which operate according to the SS7 signaling architecture to control traffic distribution between the first and second mated pairs ( 1202  and  1204 ). SS7 signaling between the mated pairs ( 1202  and  1204 ) is carried out by way of STP units  1214 , which is, in actuality, a pair of STP units. This provides each STP installation with load-sharing and backup capabilities. Thus, the links shown in  FIG. 12  as being connected to an STP are, in actuality, divided between the two STP units of an STP pair  1214 . Accordingly, it is also possible to use the active-active configuration and tandem switches with only a single pair of STP units  1214 , as opposed to the two pairs of STP units ( 1114  and  1116 ) illustrated in  FIG. 11 . 
   In operation, the loss of one member of the mated pair  1202  (going offline) will cause a reroute of services to the remaining member. Rerouting of services to the operational member due to a failure of the other mated member is automatic. Since both units share a synchronization link  1208 , they will both have identical subscriber data  1206 . The second member unit operates and updates its subscriber data  1206 . When the first member unit comes back online, the first and second units initialize communications between each other, and prior to handling traffic will perform data synchronization. Again, only the loss of a mated pair (e.g.,  1002  or  1004 ) will results in loss of service. In contrast, a conventional N+1 configuration to a single STP pair would require manual intervention of redirection to the inactive member unit. 
   What has been described above includes examples of the disclosed innovation. It is, of course, not possible to describe every conceivable combination of components and/or methodologies, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. Accordingly, the innovation is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
Redundant mechanism in a push-to-talk (PTT) realtime architecture. Redundancy is provided in core delivery systems, which are employed for the emulation of "walkie-talkie" service with circuit switched duplex calls in the carrier network. The disclosed architecture provides for geographic and/or realtime mated redundancy. In one implementation, realtime redundancy is offered in an active-active scenario, although other scenarios are possible. Similarly, redundancy is provided in a roaming gateway implementation of the PTT network.