Abstract:
A system and method for utilizing suppressed ringing with a plurality of communication devices. The system creates a suppressed ringing signal, at a remote computer, for at least one of the plurality of communication devices, implements a protocol to direct the suppressed ringing signal to the communication device through a private network and transmits the suppressed ringing signal from the remote computer, through the private network, to the communication device.

Description:
BACKGROUND OF THE INVENTION 
     This invention generally relates to telecommunication systems and methods, and more particularly, to systems and methods that perform suppressed ringing through a private branch exchange type system. 
     Certain telecommunication networks include local multi-port switches that service a plurality of individual telecommunication lines, or customer lines, to which are connected conventional telephones, facsimile communication systems, security systems, cable television converters and the like. More recently, utility service providers, such as local electric power, natural gas and water providers, are capable of accessing their usage meters located at customer locations through the telecommunication lines for the customers via a suppressed ringing protocol, such as described in U.S. Pat. No. 5,189,694 issued Feb. 23, 1993 to Garland for “Telemetry Access Arrangement” and U.S. Pat. No. 5,509,054 issued Apr. 16, 1996 to Garland for “Communication Switching System.” Both of these patents are hereby incorporated by reference with respect to such suppressed ringing and should also be referred to for general background on telephonic networks. 
     Suppressed ringing sets up a call path between a server and a device such as a telemetry interface unit (TIU) or a consumer premise equipment (CPE). The server first sends a tone that alerts (wakes up) the TIU without ringing the line connected to the TIU. Alternatively, a frequency shift keying (FSK) signal alert technique may be employed. Once the TIU is active, the server then communicates with the TIU. This allows for two way communication between the server and the TIU without bothering (ringing) the consumers at the location of the TIU or the features that the consumers may have enabled such as call forwarding, call blocking, automatic recall or other similar features. 
     Unfortunately, suppressed ringing at present only services directly connected end point devices such as TIUs. Devices which are coupled with an intermediate a private branch exchange (PBX) type communication system can not be reached because the PBX manages the call path. The PBX manages the call path because it is a concentration and routing device. 
     The problem with a PBX is that the concentration of trunking in and out does not allow direct sending of information to a specific PBX member such as a message waiting indication to light a light on the CPE. When a call is sent to a PBX member, the switch sends the information to the PBX and the PBX connects the call path if a line is available. 
     SUMMARY OF THE INVENTION 
     The above problems are solved, and a number of technical advances are achieved in the art, by implementing a system and method that notifies the private network, such as a PBX, of a received path signal from a central office switch, establishes a call path through the private network and notifies the central office switch that the call path exists. 
     In accordance with the invention, a system for utilizing suppressed ringing with a plurality of communication devices is described. The system comprises a private network and a path signal generator that generates a path signal, at a remote computer, for at least one of the plurality of communication devices. A protocol is utilized to direct the path signal to the at least one communication device through the private network. A transmitter is employed to transmit the path signal through the private network to the at least one communication device. 
     Also in accordance with the invention, a method for utilizing suppressed ringing with a plurality of communication devices is described. The method comprises the steps of creating a path signal, at a remote computer, for at least one of the plurality of communication devices, implementing a protocol to direct the path signal to the at least one communication device through a private network and transmitting the path signal from the remote computer, through the private network, to the at least one communication device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing advantageous features of the invention will be described in detail and other advantageous features will be made apparent upon reading the following detailed description that is given with reference to the several figures of the drawings, in which: 
     FIG. 1 shows an example of a conventional suppressed ringing system; 
     FIG. 2 shows a functional block diagram for the system of the invention with one central office switch; 
     FIG. 3 shows a functional block diagram for the system of the invention in a network environment with multiple central office switches; 
     FIG. 4 shows an alternative functional block diagram for the system of the invention in a network environment with multiple central office switches; and 
     FIG. 5 is a signal flow diagram showing the process performed by the system of FIG.  2 . 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows an example of a conventional suppressed ringing system. In FIG. 1, a remote computer  10  is connected to central office switch  15 , via connection  20 , and central office switch  15  is also connected, via connection  25 , to communication device  30  such as a customer premises equipment (CPE) or telemetry interface unit (TIU). 
     The remote computer  10  is any computer system that transmits information to, or receives information from, the communication device  30 . As an example, the remote computer  10  is a messaging computer and the communication device  30  is a telephone system that has voice messaging features. The remote computer  10  uses the suppressed ringing call path to communicate messaging features (without ringing) to and from the communication device  30 . 
     Alternatively, the remote computer  10  is implemented as alarm monitoring system and the communication device  30  is a remote alarm sensor located at a protected premises. Remote alarm monitoring and control systems are known that utilize telecommunications to distribute warning messages. A call is placed from the alarm monitor system to the remote alarm sensor. After the connection is made, the alarm monitor system provides telemetric or other alarm information to the remote alarm sensor. Such systems use suppressed ringing to make the connection as shown in U.S. Pat. No. 5,189,694 and U.S. Pat. No. 5,509,054 both to Garland. Additionally, reference should also be made to U.S. Pat. No. 5,394,461 issued Feb. 28,1995, to Garland for “Telemetry Feature Protocol Expansion” which also shows a termination alarm system and is hereby incorporated by reference. 
     FIG. 2 shows a block diagram for the call path system  33  of the invention. In FIG. 2, a remote computer  10  is coupled to central office switch  15 , via connection  20 , and the central office switch  15  is also coupled, via connection  35 , to a private network  40 . The private network  40  is connected to number of communication devices  45 ,  50  and  55 . Three communication devices are shown for illustration purposes only as it will be appreciated that the present invention is enabled to be performed with more or fewer communication devices. 
     The remote computer  10  is preferably any computer system that transmits information to, or receives information from, the communication devices  45 ,  50  and  55 . The central office switch  15  is a switch located at facility in which communication lines, preferably associated with a particular subscriber, are joined to telecommunication network switching equipment for connecting other subscribers to each other. An example of a central office switch  15  which may be suitably employed is a 5ESS®-2000Switch manufactured by Lucent Technologies, Inc. 
     Within the central office switch  15  is a central office reply transmitter  60  and central office router  65 . The central office router  65  preferably employs a central office notification transmitter  70 . The notification transmitter  70  sends a notification signal  75  via connection  35  to the private network  40  and the reply transmitter  60  sends a reply signal  80  to the remote computer  10  via connection  20 . 
     The private network  40  is preferably a controlled access point which is connected between the plurality of communication devices  45 ,  50  and  55  and the central office switch  15 . Examples of the communication devices  45 ,  50  and  55  are customer premises equipment (CPE), telemetry interface unit (TIU), computer modem, and any programmable communication device. Examples of the private network  40  are a private branch exchange (PBX), virtual PBX, multi-button key set switch, ISDN mutli-point switch, wireless switch, local area network (LAN) and a residential gateway. Within the private network  40  is a private network reply transmitter  85 , a private network router  90  and a private network transmitter  95 . The reply transmitter sends a private network reply signal  100  to the central office switch  15  via connection  105 . 
     FIG. 3 illustrates the call path system  33  with a plurality of central offices  110 ,  115  and  120 . Each central office  110 ,  115  and  120  consists of a central office switch  15 ,  125  and  130 . Each central office switch  15 ,  125  and  130  is coupled to at least one of the following: a digital loop carrier (DLC)  135  and  140 , a private network  40 , or a combination of communication devices  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 ,  190  and  195 . Central office switch  15  is connected to communication devices  190  and  195  directly and communication devices  180  and  185  via DLC  140 . Central office switch  125  is connected to communication devices  160 ,  165 ,  170  and  175  via the private network  40 . Central office switch  130  is connected directly to communication device  155  and indirectly, via DLC  135 , to communication devices  145  and  150 . 
     The remote computer  10  is connected, via connection  20 , to the central office  110 . Within the central office  110  is the central office switch  15  and a central office service unit  200 . The central office service unit  200  connects the remote computer  10  to the central office switches  15 ,  125  and  130 . The remote computer  10  is coupled to the central office service unit  200  via connection  20  and pass through connection  205  in the central office switch  15 . The pass through connection  205  is a dial up connection between the remote computer  10  and the central office service unit  200 . It may be a dial up, T 1 , or private line. 
     It will be appreciated that DLCs  135  and  140  are types of network transmission equipment used to provide a pair gain function. DLC  135  and  140  consist of two parts, a central office terminal and a remote terminal. As an example, the central office terminal is the central office  120  for DLC  135  and the central office  110  for DLC  140 . The central office terminal provides the multiplexing/demultiplexing function of individual voice signals to the composite multiplexed signal at the interface between the switching equipment (central office switches  15  and  130 ) and the DLC  140  and  135 . The remote terminal provides the multiplexing/demultiplexing function at the interface between the individual subscriber pairs (communication devices  145 ,  150 ,  180  and  185 ) and the DLC  135  and  140 . Alternatively, another DLC is of an integrated version type whereby the central office terminal is integrated into the central office switch. 
     FIG. 4 is an alternative illustration of the call path system  33 . The functional blocks are the same as in FIG. 3 except for the central office service unit  200 . In FIG. 4 the central office switches  15 ,  125  and  130  bypass the central office service unit  200  and connect directly to the remote computer  10  via the central office  110  so that the remote computer  10  drives the central office switches  15 ,  125  and  130  directly. 
     FIG. 5 is a signal flow diagram for the process performed by the system of FIG.  2 . The process begins at the remote computer  10 . In step  210 , the remote computer  10  transmits a request for a suppressed ringing connection to one of the communication devices  45 ,  50  and  55  via connection  20 , FIG. 2, to the central office switch  15 . In step  215 , FIG. 5, the central office switch  15  receives the request and responds by sending a request, to the remote computer  10 , for the connection information of corresponding communication device  45 ,  50  and  55 . In step  220 , the remote computer  10  transmits the requested communication information for the specific communication device  45 ,  50  and  55 . The central office switch  15 , in step  225 , transmits a notification signal  75 , FIG. 2, via connection  75 , with the notification transmitter  70  to the private network  40  that identifies the path signal and the desired communication device  45 ,  50  and  55 . This is also known as a switch cut through connection to private network  40 . For illustration purposes only communication device  45  is employed for the call path description herein. Additionally, a protocol for the private network control preferably includes application and routing control information such as PRI user to user or network specific facility messages. 
     For the cut through connection, if the connection is on dedicated suppressed ringing trunks to the private network  40  (i.e. there are suppressed ringing trunks between the remote computer  10  and the central office switch  15 ), all the calls through the private network  40  are treated as suppressed ringing calls. If instead, the connection is not on dedicated suppressed ringing trucks, inband signals may alternatively be employed. 
     The private network  40  receives the notification signal and, in step  230 , establishes a call path from the central office switch  15  to communication device  45 . The private network  40  then transmits, in step  235 , a private network reply signal  100 , FIG. 2, via connection  105 , with the reply transmitter  85  to the central office switch  15 . Once received, the central office switch  15 , in step  240 , sends a reply signal  80 , via connection  20 , to the remote computer  10  that a call path from the central office switch  15 , through the private network  40 , to the communication device  45  exits. The remote computer  10  then transmits a wake up (alert) signal, also part of the path signal, to the communication device  45  in step  245 . 
     In step  250 , the communication device  45  receives the alert signal and responds to the private network with a ready to receive notification. The private network  40 , in step  252 , then sends a ready to receive signal to the central office switch  15  and the central office switch  15 , in step  253 , sends a ready to receive signal to the remote computer  10 . In step  255 , the remote computer  10  and the communication device  45  communicate either mono-directionally, bi-directionally, full duplex or half duplex. 
     Once communication between the remote computer  10  and the communication device  45  is complete the remote computer  10 , in step  260 , stops transmitting and receiving by sending an on hook condition signal to the central office switch  15 . Additionally, the communication device  45  may stop transmission or reception by going to an on hook condition in step  265  which places the private network  40  into an on hook condition in step  270 . 
     While the specification in this invention is described in relation to certain implementations or embodiments, many details are set forth for the purpose of illustration. Thus, the foregoing merely illustrates the principles of the invention. For example, this invention may have other specific forms without departing from its spirit or essential characteristics. The described arrangements are illustrative and not restrictive. To those skilled in the art, the invention is susceptible to additional implementations or embodiments and certain of the details described in this application can be varied considerably without departing from the basic principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention are thus within its spirit and scope.