Patent Publication Number: US-11663902-B2

Title: Method and system for providing alternate network access

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/852,072, filed Apr. 17, 2020, which is a continuation of U.S. patent application Ser. No. 16/156,448, filed Oct. 10, 2018, issued as U.S. Pat. No. 10,672,254 on Jun. 2, 2020, which is continuation of U.S. patent application Ser. No. 15/452,149, filed Mar. 7, 2017, issued as U.S. Pat. No. 10,140,840 on Nov. 27, 2018, which is a continuation of U.S. patent application Ser. No. 15/222,416, filed Jul. 28, 2016, now abandoned, which is a continuation of U.S. patent application Ser. No. 13/725,607, filed Dec. 21, 2012, issued as U.S. Pat. No. 9,510,065 on Nov. 29, 2016, which is a continuation of U.S. patent application Ser. No. 11/738,862, filed Apr. 23, 2007, issued as U.S. Pat. No. 8,451,986 on May 28, 2013. 
    
    
     BACKGROUND 
     Security systems alert occupants of a dwelling and emergency authorities of a violation of premises secured by the security system. A typical security system includes a controller connected by wireless or wired connections to sensors deployed at various locations throughout the secured dwelling. In a home, sensors are usually deployed in doorways, windows, and other points of entry. For example, motion sensors can be placed strategically within the home to detect unauthorized movement, while smoke and heat sensors can detect the presence of fire. 
     Security systems are usually connected to a central monitoring service system via a telecommunications line coupled to a public switched telephone network (PSTN). The central monitoring service system can be maintained by a security service provider and continuously monitors all activated subscriber security systems for alarms. Sensor activity occurs when a sensor detects, for example, an opening of a door or window, or presence of movement, or a fire. Sensor activity causes the sensor to send a signal to the controller of the security system. Responsive to receiving the signal, the controller can determine whether the signal represents an alarm condition and, if so, issue an audible alarm to alert the occupants of the dwelling and can originate a data transmission to the central monitoring service system via the telecommunications line. Upon receiving notification of an alarm, the central monitoring service system can determine the type of activity, attempt to contact the dwelling occupants, and alert appropriate authorities of an emergency situation. 
     Typically, the telecommunications line interconnecting the security system to the central monitoring service system is the dwelling occupant&#39;s telephone line. This line usually emanates and is accessible from the exterior of the dwelling. It is this telecommunications line which delivers a security breach signal to the central monitoring service system via a PSTN. 
       FIG.  1    is a simplified block diagram illustrating a typical connection between a PSTN and a security system. Building  100  is coupled to PSTN  110  via a network interface device (NID)  120 . Typically, NID  120  demarcs the hardware associated with PSTN  110  and the hardware (e.g., building wiring) associated with building  110 . When building  100  has a security system, or is configured to accommodate a security system, NID  120  is coupled via building wiring (e.g., twisted pair) to an RJ31X jack  130 . The RJ31X jack is typically inserted between an NID and the first telephone jack within a building. An alarm controller unit  140  for a security system can be coupled to the building wiring via RJ31X jack  130 . As will be discussed more fully below, this permits a security system to disconnect phones in the building (e.g., coupled to telephone jacks  150 - 180 ) in order to transmit an alarm signal to a central monitoring service system via PSTN  110 . An RJ31X jack also allows a building&#39;s phone system to behave normally if a security system is not connected to the RJ31X jack. 
       FIG.  2    is a simplified block diagram illustrating an example of a typical voice over Internet protocol (VOIP) connection to a building&#39;s telephone wiring. Building  100  is still configured to be coupled to PSTN  110  via NID  120  which is then coupled to RJ31X jack  130 . RJ31X jack  130  has connections to both an alarm controller unit  140  and a set of connected phone jacks  150 - 180  (e.g., in a daisy-chain configuration).  FIG.  2    illustrates that a telephone jack  180  is further coupled to an analog telephone adapter (ATA)  210 . ATA  210  converts telephone analog signals to digital signals that can be transmitted on a broadband network (e.g., Internet  230 ). ATA  210  is coupled to a broadband modem  220  (e.g., a cable modem or DSL modem) which is further coupled to a wide area network such as Internet  230 . In order for a proper installation of VOIP telecommunications, building  110  should be disconnected from PSTN  110  in order to avoid, for example, improper voltages associated with VOIP from being transmitted onto PSTN  110 . Disconnecting is typically performed at NID  120  by manually disconnecting a linkage between PSTN  110  and the building wiring at a demarc point within NID  120 . One drawback of a typical VOIP connection is that severing the connection between building  100  and PSTN  110  typically requires a service visit by a representative of the provider of PSTN  110  to perform the disconnection. 
     Another drawback of a VOIP connection such as that illustrated in  FIG.  2    is alarm controller unit  140  cannot perform the task of disconnecting the home phones prior to sending out an alarm signal. This is because the security system is no longer between the building telephone wiring and the external telecommunications network. A further disadvantage of using a legacy security system in a VOIP environment is that such security systems are typically unreliable in a VOIP environment. VOIP data compression as well as multiple analog-to-digital and digital-to-analog conversions typically involved in VOIP transmission can distort alarm signals sent by a security system, thereby making them unusable by the central monitoring service system. 
     It is therefore desirable to provide a solution in which a legacy security system can function in a VOIP environment without loss of data. It is further desirable to provide a mechanism by which a switch over from PSTN-based telecommunications to an alternative technology-based telecommunication (e.g., broadband or cellular) can be provided without having a person manually disconnect a building from a PSTN by severing a connection within an NID. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. 
         FIG.  1    is a simplified block diagram illustrating a typical connection between a public switched telephone network (PSTN) and a building security system. 
         FIG.  2    is a simplified block diagram illustrating an example of a typical voice over Internet protocol (VOIP) connection to a building&#39;s telephone wiring. 
         FIG.  3    is a simplified block diagram illustrating an example of typical telecommunications connections between an RJ31X jack and an alarm controller unit for a legacy security system. 
         FIG.  4    is a simplified block diagram illustrating a communications unit configured to provide alternate network connectivity in accord with embodiments of the present invention. 
         FIG.  5    is a simplified block diagram of components of an alarm system controller unit coupled to a communications unit in accord with embodiments of the present invention. 
         FIG.  6    is a simplified flow diagram illustrating an example of a process for configuring a communications unit to provide alternative telecommunication modes in accord with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention provide a communications unit that can be coupled to a building&#39;s telecommunication wiring to provide an automated mechanism for isolating the building&#39;s wiring from a PSTN, while also providing a telecommunications connection to an alternative communications network via, for example, broadband or cellular networks. Embodiments of the present invention can be configured to be coupled with an alarm controller unit of a legacy security system, thereby permitting the legacy security system to communicate with a remote server system without loss of alarm data. Embodiments of the invention will also permit the legacy security system to provide normal disconnect functionality of building telephones from an outgoing telecommunications line while an alarm condition is present. 
       FIG.  3    is a simplified block diagram illustrating some of the telecommunications connections between an RJ31X jack  130  and an alarm controller unit for a legacy security system  140 . As discussed above, RJ31X jack  130  is coupled to building wiring between a PSTN and the telephone jacks within the building. As illustrated in  FIG.  3   , Line (a) is coupled through RJ31X jack to the PSTN (via an NID), while Line (b) is coupled through the RJ31X jack to the building telephone jacks. If no security system were present, the RJ31X jack would short Lines (a) and (b) together thereby allowing the building telephone wiring to communicate with the PSTN. 
     As illustrated in  FIG.  3   , Lines (a) and (b) enter alarm controller unit  140  and are coupled to an automated switch  310 . Automated switch  310  is controlled by alarm processor  320 . Alarm processor  320  is also connected via Line (a) to the PSTN. When no alarm is present, alarm processor  320  places switch  310  in a closed state, thereby allowing normal telecommunications operations between the building telephone wiring and the PSTN. During an alarm condition, alarm processor  320  sets switch  310  in an open state, thereby disconnecting any telephones connected to the building phone jacks from the PSTN. Such a disconnection prevents an intruder in the building from stopping an alarm dial out by raising a handset on a phone. Once switch  310  is placed in an open state, alarm processor  320  can dial out an alarm signal on Line (a) to a central monitoring service system coupled to the PSTN. 
       FIG.  4    is a simplified block diagram illustrating a communications unit  400  configured to provide alternate network connectivity in accord with embodiments of the present invention. Lines (a) and (b) are provided from RJ31X jack  130  to communications unit  400 . Line (a) is connected through RJ31X jack  130  to a PSTN, while Line (b) is connected through the RJ31X jack to building telephone wiring. Lines (a) and (b) are coupled to a switch  410  which is controlled by Communication Processor/ATA  430 . Line (b) is also coupled to a switch  420 , which is also controlled by Communication Processor/ATA  430 . Line (c) is coupled to both switch  420  and switch  310  in alarm controller unit  140  (discussed above with regard to  FIG.  3   ). Thus, Line (c) in  FIG.  4    corresponds to Line (b) illustrated in  FIG.  3    with regard to switch  310 . As with  FIG.  3   , switch  310  is controlled by alarm processor  320 . The other pole of switch  310  is coupled via Line (d) to Communication Processor/ATA  430 . Thus, Line (d) in  FIG.  4    corresponds to Line (a) of  FIG.  3    and Communication Processor/ATA  430  can be configured to provide responses to alarm processor  320  that would be expected from the PSTN over Line (d). 
     Communication Processor/ATA  430  can be configured to provide a plurality of outbound communication modes. As illustrated, Communication Processor/ATA  430  is coupled to Line (a) to enable provision of an outgoing PSTN connection. Communication Processor/ATA  430  is further coupled to a network interface  440 , which enables provision of a two-way communication to a broadband network. For example, network interface  440  can be an Ethernet interface which is further coupled to a broadband modem (not shown). Alternatively, network interface  440  can be a broadband modem itself, which is then coupled to a broadband connection leaving the building. Communication Processor/ATA  430  can be further connected to a cellular interface  450  for communication to a private cellular network (not shown) that can ultimately give a connection to an external network (also not shown). As will be discussed below, use of a broadband connection or a cellular connection can provide an alarm signal to a remote server system coupled to an external network, such as the Internet. 
     Switches  410  and  420  are configured to be placed in an opened or closed state depending upon the desired communications mode. For example, if the building&#39;s telephone system is to be connected to the PSTN, then switch  410  is placed in a closed state by Communication Processor/ATA  430 , while switch  420  is placed in an open state. Even though no communication signal is provided over Line (c) to alarm controller unit  140 , the legacy security system continues to function in response to an alarm condition as previously discussed. That is, switch  310  is held in a closed state until an alarm condition is detected by alarm processor  320 . Upon detection of an alarm condition, switch  310  is placed in an open state and alarm processor  320  transmits an alarm signal along Line (d) to Communication Processor/ATA  430 , which can respond to the alarm processor in a manner that simulates an expected response from the PSTN. As discussed more completely below, Communication Processor/ATA  430  can interpret the alarm signal and in turn transmit the alarm signal on a selected communication path. 
     If the selected communication path is PSTN, then Communication Processor/ATA  430  can place switch  410  in an open state and transmit the alarm signal along Line (a) to the PSTN in a manner similar to that of the alarm controller unit  140 . If the selected communication mode is broadband, then Communication Processor/ATA  430  can interpret the alarm signal and transmit an appropriate data stream through network interface  440  to a remote server system coupled to the broadband network. Similarly, Communication Processor/ATA  430  can transmit an appropriately formatted data stream to a cellular network via cell interface  450 . In either the broadband or cellular configuration, switch  410  does not need to be opened because use of the building phone system will have no affect on outgoing communication. 
     Communications unit  400  can also be configured to provide alternate network access for building telephones, such as VOIP or cellular telephone. Again, configuration of switches  410  and  420  provides this access. For a VOIP/cellular telephone configuration, switch  410  is placed in an open state by Communication Processor/ATA  430 . By opening switch  410 , this effectively isolates the building telephone wiring (coupled via Line (b)) from the PSTN (coupled via Line (a)). In addition, switch  420  is placed in a closed state by Communication Processor/ATA  430 . Thus, signals from telecommunication devices coupled to building telephone jacks arrive at communications unit  400  through Line (b), pass through switch  420 , continue along Line (c) to alarm controller unit  140 , pass through switch  310  (which is held in a closed state when no alarm is present) and are provided to Communication Processor/ATA  430  via Line (d). Communication Processor/ATA  430  can then process the analog telephone signals (e.g., in a manner standard for VOIP) in preparation to be transmitted to the broadband network coupled to network interface  440 . Alternatively, Communication Processor/ATA  430  can process the analog signals received on Line (d) in a manner appropriate for transmission via cellular interface  450 , if cellular telephone connectivity is desired. 
     In the configuration allowing alternate telecommunications network access discussed above, upon detection of an alarm condition by alarm controller unit  140 , alarm processor  320  places switch  310  in an open state, thereby disconnecting the building telephones, and then transmits alarm condition information on Line (d) to Communication Processor/ATA  430 , which will then transmit the alarm information along the selected communication path. It should be noted, that because the PSTN does not need to be disconnected at the NID, if PSTN service is still otherwise available, then Communication Processor/ATA  430  can transmit alarm information out along Line (a) to a central monitoring service system over the PSTN, while still being configured to provide alternate network access for telecommunications from the building phone system. By holding switch  410  in an open state, communications unit  400  isolates the building telephone wiring from the PSTN. 
     As will be discussed with regard to an embodiment below, communications unit  400  can be configured to be in communication with a remote server system over an external network. This communication mode is bidirectional, thereby allowing control information to be provided to the communications unit and any security system coupled to the communications unit. Control information can be sent by the remote server system to the communications unit  400  directing Communication Processor/ATA  430  to operate in a selected mode (i.e., PSTN, VOIP, and cellular telephone). Thus, a user of communications unit  400  can contact a provider of the remote server system and request, for example, VOIP service to be activated on communications unit  400 . A signal can then be sent by the remote server system instructing the communications unit to configure switches  410  and  420  in a manner appropriate to the selected mode and all configuration necessary for that mode is provided without further user interaction. 
     It should be noted that such reconfiguration of a building phone system between one of a variety of modes can be done much more efficiently than traditional methods. This is due, in part, to disconnection and reconnection to the PSTN not requiring manual disconnection of circuits at the NID. 
     It should further be noted that while the above discussion illustrates a connection to alarm controller unit  140 , no security system is necessary to the alternate network access provision of the present invention. Lines (c) and (d) can, for example, be shorted together to provide a circuit between switch  420  and Communication Processor/ATA  430 . In such a configuration, Communication Processor/ATA  430  can provide just the switch configuration control and any necessary data conversion between the analog signal from the building telephone system to the chosen external network. 
     Example Embodiment of Communications Unit 
       FIG.  5    is a simplified block diagram of components of a legacy alarm system coupled to a communications unit in accord with embodiments of the present invention. Alarm controller unit  505  includes an alarm processor  510  (e.g., a microprocessor) coupled to sensors  515 ( 1 )-(N). Alarm processor  510  is coupled via keypad bus  525  to keypad processor  535  within keypad  530 . Keypad  530  includes keys  540  through which control codes can be entered to alarm processor  510 . Communications unit  545  provides a communications processor  550  that is coupled to alarm processor  510  and keypad processor  535  via keypad bus  525 . Thus, communications processor  550  can exchange data with alarm processor  510  using a serial digital protocol of keypad bus  525 . Communications processor  550  can be configured to automatically determine the type of serial digital protocol being used in communications between alarm processor  510  and keypad processor  535  as part of an initial configuration of communications unit  545  upon being coupled to the keypad bus. 
     Communications processor  550  is also coupled to alarm controller unit  505  via telecommunications link  555 , which is coupled to the outgoing port of telephone line interface  520 . Telecommunications link  555  corresponds to Line (d) of  FIG.  4   , wherein switch  310  of  FIG.  4    is embodied within telephone line interface  520 . Communications processor  550  is further coupled to PSTN  560  by telecommunications link  563 . Telecommunications link  563  corresponds to Line (a) of  FIG.  4   , wherein communications processor  550  corresponds to Communications Processor/ATA  430  of  FIG.  4   . Communications processor  550  then serves as an intermediary between alarm controller unit  505  and PSTN  560 . It is through this link that communications processor  550  can provide communication from alarm controller unit  505  to a remote server system  565  via the PSTN, should that be a selected communication mode (as described below). 
     Remote server system  565  can be a network-coupled computer system that provides, in part, responsive communication to information received from communications unit  545 . Such responsive communication can be provided to, for example, the user of the alarm system (e.g., a homeowner) or to emergency responders to alarm conditions. Remote server system  565  can also provide communication to communications unit  545 , including, for example, updates and configuration information such as telecommunications configuration information discussed above with respect to  FIG.  4   . 
     Communications processor  550  can also be coupled to a cellular interface  570  that can provide cellular transmission to a cell tower  575  that is also coupled, directly or indirectly, to a private cellular network  580 , which is further coupled to a network  585 . Through this link, communications processor  550  can provide a cellular transmission communication mode to server system  565 , which is also coupled to network  585 , or cellular telephone connectivity as discussed above with respect to  FIG.  4   . 
     Communications processor  550  can also be coupled to a network interface  590 . Network interface  590  can provide a broadband connection to network  585  (e.g., the Internet), which is also coupled to server system  565 . Through network interface  590 , communications processor  550  can provide a broadband communications mode to server system  565 , or VOIP-type telecommunications for building telephone systems. 
     In alternate embodiments of communications unit  545 , communications processor  550  can be coupled to other communication interfaces that can provide wireless broadband, and the like. 
     Communications processor  550  can monitor all of the available communication modes to determine which communication mode is the best for transmitting security system data to and from server system  565  at any point in time. For example, the communications processor, through network interface  590 , can monitor whether there is an active connection to network  585 . Such monitoring can be performed by, for example, by periodically establishing, or attempting to establish, a connection with server system  565  and monitoring a heartbeat signal. Alternatively, the communications processor can determine availability and viability of a network connection to the server system using, for example, network echo packets (e.g., pinging). Similarly, through cellular interface  570 , communications processor  550  can periodically establish, or attempt to establish, a connection with server system  565  through private cellular network  580  and network  585 . With regard to connections via PSTN  560 , the communications processor can, for example, determine whether there is an appropriate voltage over the telecommunications link  563  from the PSTN. In an event of a voltage drop on telecommunications link  563 , the communications processor can interpret such a drop as an event that needs to be communicated to the remote server (over either the broadband or cellular connection). 
     As the communications processor determines the best communication mode for security system information, that mode is then used for communication between communication unit  545  and server system  565  until a determination is made that an alternate communication mode is more appropriate. Alternatively, the communications processor can be configured to give primary preference to a particular communications mode (e.g., broadband), and then secondary preference to a different communications mode (e.g., cellular), and so on. In such a case, the communications processor will use the primary communications mode for transmitting and receiving security system information unless that communications mode is unavailable and then switch to a secondary (or lower) communications mode, depending upon availability of that mode. 
     As stated above, communications processor  550  and alarm controller unit  505  are coupled over telecommunications link  555  in order for the communications processor to function as an intermediary between the alarm controller unit and PSTN  560 . In a legacy system, when alarm processor  510  detects an alarm situation, alarm processor  510  instructs telephone line interface  520  to dial out over PSTN  560  to communicate with the central monitoring service system. As discussed above, at substantially the same time, alarm processor  510  also instructs the telephone line interface to disconnect building telephones from the line (e.g., by setting switch  310  to an open state). Communications processor  550  can simulate the phone service and the central monitoring system and interpret the alarm signals provided by alarm processor  510 . Alarm processor  510  provides such communication using, for example, a ContactID format. Communications processor  550  can read the data supplied by alarm processor  510  over the telecommunications link, interpret that data, and transmit an appropriate signal over the chosen communication mode to server system  565 . 
     Communications processor  550  can also interpret signals provided by alarm processor  510  over keypad bus  525 , and provide that information to server system  565  over the chosen communication mode. As stated above, such information can include arm/disarm indicators, zone trip information, system trouble (e.g., low battery, clock reset, no power), and the like. 
     Communications processor  550  can also receive information provided by server system  565  over a communication mode selected by the server system. Communications processor  550  can interpret that received information and format the information for the appropriate serial digital protocol of keypad bus  525 . Communications processor  550  can then provide the information to alarm processor  570  over keypad bus  525 . Through such communication, communications processor  550  emulates keypad communication to alarm processor  510 . Thus, there is no need to reprogram the legacy alarm system to allow the legacy alarm system to be controlled through communication unit  545 . 
     Example Configuration Process 
       FIG.  6    is a simplified flow diagram illustrating an example of a process for configuring a communications unit (e.g.,  400 ) in accord with embodiments of the present invention. A communications unit receives configuration data ( 610 ), for example, from a remote server system. The communications unit can then determine whether the configuration requires outgoing telecommunication via PSTN ( 620 ). If the configuration is for PSTN-based communication, then the communications unit couples the PSTN to the building telephone wiring ( 630 ). As discussed above, such a coupling can be accomplished, for example by placing switch  410  in a closed state. Analog signals received from the building telephone wiring can then be provided to the PSTN ( 640 ). 
     If the outgoing telecommunications are not to be provided by a PSTN, then the communications unit can isolate the PSTN from the building telephone wiring ( 650 ). Such isolation of the PSTN can be performed automatically by placing, for example, switch  410  in an open state as illustrated and discussed above with regard to  FIG.  4   . Isolation of the PSTN from the building wiring in this manner prevents signals and voltages from the building wiring to enter the PSTN network. 
     The configuration data is then reviewed to determine whether outgoing communication is to be via VOIP ( 660 ). If VOIP is the chosen outgoing communication method, then analog signals received from the building telephone wiring are provided to an ATA for conversion to digital signals ( 670 ). In communication unit  400  illustrated above, the ATA is integral with Communications Processor/ATA  430 . The digital signals are then provided to a network interface for transmission over a broadband connection ( 680 ). If the outgoing communication is not by VOIP, then the analog signals can be provided to a cellular interface for conversion and transmission over a cellular network ( 690 ). 
     Any configuration of a communications unit for a particular outgoing telecommunications mode can remain in place until a new set of configuration data is received by the communications unit indicating that a different telecommunications mode should be provided. Configuration information can be stored, for example, in a nonvolatile memory coupled to Communication Processor/ATA  430 . In addition, although the above figures and discussion provides PSTN, VOIP, and cellular as alternate telecommunications modes, it should be recognized that these modes are provided as examples and that embodiments of the present invention are not limited to providing just the three telecommunications modes discussed above. Various types of analog signal conversion mechanisms can be provided to a communications unit  400  and either be integrated with a Communication Processor/ATA  430  or coupled thereto. 
     OTHER EMBODIMENTS 
     The present invention is well adapted to attain the advantages mentioned as well as others inherent therein. While the present invention has been depicted, described, and is defined by reference to particular embodiments of the present invention, such references do not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alteration, and equivalents in form and function as will occur to those ordinarily skilled in the pertinent arts. The depicted and described embodiments are examples only, and are not exhaustive of the scope of the invention. 
     The foregoing describes embodiments including components contained within other components (e.g., the various elements shown as components of communications unit  210 ). Such architectures are merely examples, and, in fact, many other architectures can be implemented which achieve the same functionality. In an abstract but still definite sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being “operably connected” or “operably coupled” to each other to achieve the desired functionality. 
     The foregoing detailed description has set forth various examples of the present invention via the use of block diagrams, flow charts, and examples. It will be understood by those within the art that each block diagram component, flow chart step, operation and/or component illustrated by the use of examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or any combination thereof. 
     The above description is intended to be illustrative of the invention and should not be taken to be limiting. Other embodiments within the scope of the present invention are possible. Those skilled in the art will readily implement the steps necessary to provide the structures and the methods disclosed herein, and will understand that the process parameters and sequence of steps are given by way of example only and can be varied to achieve the desired structure as well as modifications that are within the scope of the invention. Variations and modifications of the embodiments disclosed herein can be made based on the description set forth herein, without departing from the scope of the invention. 
     Consequently, the invention is intended to be limited only by the scope of the appended claims, giving full cognizance to equivalence in all respects. 
     Although the present invention has been described in connection with several embodiments, the invention is not intended to be limited to the specific forms set forth herein. On the contrary, it is intended to cover such alternatives, modifications, and equivalents as can be reasonably included within the scope of the invention as defined by the appended claims.