Patent Publication Number: US-2005117568-A1

Title: Speech communication system and communication apparatus for speech communication system, and telephone exchange apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-400889, filed Nov. 28, 2003, the entire contents of which are incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a speech communication system for allowing speech communication to be made between telephone terminals via an IP (Internet Protocol) network for allowing the transmission of, for example, a speech packet and a communication apparatus for this speech communication system as well as a telephone exchange apparatus for improving an effective utilization rate of speech channels over the IP network.  
      2. Description of the Related Art  
      In recent years, a network telephone system (IP telephone system) has been beginning to be used which can interactively transmit/receive an image and speech as packet data in real-time over an IP network.  
      In this IP telephone system, IP telephone terminals are connected to the IP network and a packet network is connected to the public switched telephone network, such as analog telephone circuit lines or public network, through a gateway or a main apparatus, while, in the IP telephone terminals and gateway, a protocol conversion, data format conversion, etc., are made to allow speech communication to be made between the IP telephone terminals and between the IP telephone terminal and the public switched telephone network.  
      In this kind of system, an IP address is allocated to a plurality of IP network-connected interfaces in the main apparatus. For example, a caller on the IP network-connected telephone terminal (dial call node) dials in the node ID+extension number so as to make speech communication to a telephone set (connection destination node) on the main apparatus. In this case, the dial number is connected to a corresponding IP address and this is notified to the main apparatus of a connection destination. The main apparatus of the connection destination decides whether or not there is any available port. Here, if there is no available port, the caller on the dial call node takes a re-connection procedure with the use of another IP address. This takes a lot of time and labor from when the caller on the dial call node sends a dial call to until a communication link is established to a called party on the connection-destination terminal.  
      In order to solve foregoing problem, the following method has been proposed (For example, JPN PAT APPLN KOKAI PUBLICATION NO. 2003-169079). According to which, while monitoring the state of each interface through a signaling (call controller) section, an incoming call is received.  
      In the above-mentioned method, the states of a plurality of interfaces are monitored at all times and an incoming call is received through an available interface under a signaling section, so that a greater processing burden is exerted on the signaling section. It is, therefore, necessary to provide an expensive main apparatus per se.  
     BRIEF SUMMARY OF THE INVENTION  
      It is accordingly the object of the present invention to provide a speech communication system and a communication apparatus for such speech communication system, as well as a telephone exchange apparatus, which can alleviate a processing burden and reduce an operation cost and, further, can ensure prompt and proper call reception processing.  
      According to an aspect of the present invention, there is provided a speech communication system comprising: a plurality of connection apparatuses to connect a circuit line and a communication network transmitting a plurality of speech packets and control packets, the circuit line being connected at least one of terminal and transmitting a corresponding speech signal, to communicate between the terminal and the communication network, respectively; and a controller which controls to forward an incoming call to another connection apparatus, when the incoming call arrives via the connection network and there exists no available circuit line, in each the connection apparatuses.  
      According to another aspect of the present invention, there is provided a communication apparatus for use as a plurality of connection apparatus in a speech communication system including the connection apparatuses to connect a circuit line and a communication network transmitting a plurality of speech packets and control packets, the circuit line being connected at least one of terminal and transmitting a corresponding speech signal, respectively; comprising: a controller which controls to forward an incoming call to another connection apparatus, when the incoming call arrives via the connection network and there exists no available circuit line.  
      According to yet another aspect of the present invention, there is provided a telephone exchange apparatus comprising: a first interface to connect a circuit line being connected at least one of terminal and transmitting a corresponding speech signal; a plurality of second interfaces to connect a communication network including a plurality of speech channels allowing a transmission of a plurality of speech packets and at least one of control channel allowing a transmission of a plurality of control packets; a exchanger which connects between the first interface and at least one of the second interfaces according to a call setting request; and a controller which controls to forward an incoming call to another second interface, when the incoming call arrives through the control channel of the connection network and there exists no available communication channels, in each the second interfaces.  
      Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
      The accompanying drawings, which are incorporated in and constitute a part of the specification, embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.  
       FIG. 1  is a view showing a schematic arrangement of an IP telephone system according to a first embodiment of the present invention;  
       FIG. 2  is a view showing one practical management table for managing the state of a speech circuit in each interface in an IP network in  FIG. 1 ;  
       FIG. 3  is a view showing one practical forward destination table in the interfaces of the IP network in  FIG. 1 ;  
       FIG. 4  is a view showing another practical management table for managing the states of speech circuits in the interfaces of the IP network;  
       FIG. 5  shows a flowchart showing call forward processing performed by a control section in the IP interface in  FIG. 1 ;  
       FIG. 6  is a view showing a schematic arrangement of an IP telephone system according to a second embodiment of the present invention;  
       FIG. 7  is a view showing one practical state table stored in a state data storage section in the interfaces of the IP network in  FIG. 6 ;  
       FIG. 8  is a view showing a flowchart showing a state information notifying processing procedure performed by a control section in the interfaces of an IP network in  FIG. 6 ;  
       FIG. 9  shows a flowchart showing a state table updating procedure performed by a control section in the interface of an IP network in  FIG. 6 ;  
       FIG. 10  is a block diagram showing a schematic arrangement of an IP telephone system according to a third embodiment of the present invention;  
       FIG. 11  is a block diagram showing a schematic arrangement of an IP telephone system according to a fourth embodiment of the present invention;  
       FIG. 12  shows a flowchart showing an incoming call forwarding processing procedure performed by a control section in the interfaces of an IP network in  FIG. 11 ; and  
       FIG. 13  is a block diagram showing a schematic arrangement of an IP telephone system according to a fifth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      With reference to the drawings, the embodiments of the present invention will be described in more detail below.  
     First Embodiment  
       FIG. 1  shows a schematic arrangement of an IP telephone system according to the first embodiment of the present invention.  
      As shown in  FIG. 1 , the IP telephone system is so formed that, to a main apparatus  1 A, an IP network IPN is arbitrarily connected and the main apparatus  1 A has its extensions through which a plurality of telephone terminals T 1  to Ti are arbitrarily connected. It is to be noted that the IP network IPN has, for each IPN interface, a plurality of speech channels and an equal number of control channels or at least one control channel.  
      The main apparatus  1 A further includes a signaling section (a call controller)  11 , IPN interfaces  12 - 1  to  12 - n  (hereinafter referred to as IPN IF&#39;s  12 - 1  to  12 - n ), extension interfaces  13 - 1  to  13 - i  (hereinafter referred to as extension IF 13 - 1  to IF 13 - i , and a Trunk line interface  14  (hereinafter referred to as a trunk line IF 14 ). The signaling section  11 , IPN IF&#39;s  12 - 1  to  12   n , extensions IF&#39;s  13 - 1  to  13 - i , and trunk line IF 14  are connected through a speech bus  15  and control bus  16 .  
      The signaling section  11  allows an arbitrary exchange connection to be made between the IPN IF&#39;s  12 - 1  to  12 - n  and the extensions IF&#39;s  13 - 1  to  13 - i , between the IPN IF&#39;s  12 - 1  to  12 - n  and the trunk line IF 14 , between the extension IF&#39;s  13 - 1  to  13 - i  and the trunk line IF 14  and between these extensions IF&#39;s  13 - 1  to  13 - i  and allows the control of a speech signal/control signal to be made between the IPN IF&#39;s  12 - 1  to  12 - n  on one hand and extensions IF&#39;s  13 - 1  to  13 - i  and trunk line IF 14  on the other.  
      The IP network IPN is connected, as required, to the IP IF&#39;s  12 - 1  to  12 - n . The IP IF&#39;s  12 - 1  to  12 - n  perform an interface operation relating to the IP network IP network IPN. The IPN IF&#39;s  12 - 1  to  12 - n  allow the transfer of various control information relating to the interface operation to be made to and from the signaling section  11  through the control bus  16 .  
      The telephone terminals T 1  to Ti are connected, as required, to the extensions IF&#39;s  13 - 1  to  13 - i . The extensions IF&#39;s  13 - 1  to  13 - i  perform an interface operation relating to the telephone terminals T 1  to Ti connected thereto. Further, the extensions IF 13 - 1  to  13 - i  allow the transfer of various control information relating to the above-mentioned interface operation to be made to and from the signaling section  11  through the control bus  16 .  
      A public network PNW is connected, as required, to the trunk line IF 14 . The trunk line IF 14  performs an interface operation relating to the public network PNW connected thereto. Further, the trunk line IF 14  allows the transfer of various control information relating to the interface operation to be made to and from the signaling section  11  through the control bus  16 .  
      Incidentally, the respective IPN IF&#39;s  12 - 1  to  12 - n  have speech processing sections  121 - 1  to  121 - n  and control sections  122 - 1  to  122 - n , respectively. Here, an explanation will be made below by taking the speech processing section  121 - 1  and control section  122 - 1  as a representative example.  
      The speech processing section  121 - 1  has a speech circuit of, for example, 16 channels and, under control of the control section  122 - 1 , allows a conversion to be made from a speech packet to a PCM signal or from a PCM signal to a speech packet.  
      The control section  122 - 1  allows the transmission/reception of a control signal to/from the signaling section  11  and has a management table under which the states of the speech circuits are managed. When an incoming call reaches the corresponding telephone terminal T 1  from the IP network IPN, the control section  122 - 1  decides whether or not there exists any available speech circuit before any associated information is passed to and from the signaling section  11 . If there are no available speech circuits, the incoming call is forwarded to the IPN IF 12 - 2  (IP address: I/f 2 - 2 ) based on a forward destination table shown in  FIG. 3 .  
      In the IPN IF 2 - 2 , the control section  122 - 2  has, as shown in  FIG. 4 , a management table for managing the states of the speech circuits and, upon receipt of any incoming call, decides whether or not there, exists any available speech circuit. If it is decided that the speech circuit  2  is available, then a communication link is established to the incoming call destination telephone terminal T 1  with the use of the speech circuit  2 .  
      The operation of the IP telephone system thus structured will be explained below.  
      Now it is assumed that any incoming call from the IP network IPN to the telephone terminal T 1  arrives at the IPN IF 12 - 1  of the main apparatus.  
      The control section  122 - 1  of the IPN IF 12 - 1  performs control processing shown in  FIG. 5  and monitors whether or not any incoming call arrives (step ST 5   a ). Here, if Yes, the control section  12 - 1  decides whether or not there is any available speech circuit in the speech processing section  121 - 1  based on control table (step ST 5   b ).  
      Here, since the speech circuits of the IPN IF 12 - 1  are all busy, the control section  122 - 1  refers to the forward destination IP address from the forward destination table (step ST 5   c ) and decides whether or not there is any forward destination IP address (step ST 5   d ). Here, if there is no forward destination IP address, a notice is sent to a dial call side to the effect that re-connection be made by a different IP address and disconnection processing is done.  
      If, on the other hand, there exists any forward destination IP address, the control section  122 - 1  forwards an incoming call through the control bus  16  to the forward destination IPN IF 12 - 1  (step ST 5   e ).  
      The control section  122 - 2  of the IPN IF 12 - 2 , after performing the processing at step ST 5   a , decides whether or not there is ay available speech circuit in the speech processing section  121 - 2  and, when there exists any available speech circuit, the incoming call is forwarded to the signaling section  11  through the control bus  16  (step ST 5   f ).  
      The signaling section  11  forwards the incoming call to the telephone terminal T 1 , notifying the arrival of the incoming call. When the talker on the telephone terminal T 1  performs a connect operation to the incoming call, the control section  122 - 2  of the IPN IF 12 - 2  sends back speech port information containing a self IP address, as a connect massage, to the caller side. Thus, a communication link using the available speech circuit is established between the telephone terminal on the caller side and the telephone terminal T 1  on the called party side to allow speech communication to be made between the telephone terminal on the caller side and the telephone terminal T 1 .  
      The main apparatus  1 A of the above-mentioned embodiment is so operated that, if any incoming call arrives through the control channel of the IP network IPN, whether or not there is any available speech circuits is decided by the incoming call received IPN IF 12 - 1  and, if all the speech circuits are busy, the incoming call is forwarded to another IPN IF 12 - 2  without passing through the signaling section  11 . Until any available speech circuit is found, the incoming call forward processing is done in a repeated way.  
      Therefore, it is not necessary for the caller side to memorize any IP address for each of the IPN IF 12 - 1  to  12 - n  in the main apparatus  1 A and, by simply inputting one representative IP address, connection processing is automatically made relative to the connection destination telephone terminal T 1 . It is, therefore, possible to make a connection to the connection destination telephone terminal T 1  for a short period of time to an extent not passing through the signaling section for processing.  
      On the other hand, it is possible for the incoming call receiving side to alleviate the processing burden on the signaling section  11  required for the incoming call forward processing and largely reduce the operation cost. Further, it is also possible to enhance the effective utilization rate of the speech circuit because another available speech circuit in the IPN IF 12 - 2  can be used.  
      Further, according to the first embodiment, for each of the IPN IF&#39;s  12 - 1  to  12 - n , the forward destination is fixedly decided and, even where a plurality of incoming calls involve in the same time zone, it is possible to forward these incoming calls in a parallel way and effectively effect the forwarding control of these incoming calls.  
     Second Embodiment  
       FIG. 6  is a schematic view showing an IP telephone system according to a second embodiment of the present invention. In  FIG. 6 , the same reference numerals are employed to designate parts or elements corresponding to these shown in  FIG. 1 .  
      A main apparatus  1 B includes IP network interfaces  17 - 1  to  17 - j  (hereinafter referred to as IPN IF&#39;s  17 - 1  to  17 - j ). The IPN IF&#39;s  17 - 1  to  17 - j  include speech processing sections  171 - 1  to  171 - j , control sections  172 - 1  to  172 - j  and state data storage sections  173 - 1  to  173 - j  (hereinafter referred to storage sections  173 - 1  to  173 - j ). Here, the IPN IF 17 - 1  will be explained below as a representative example.  
      The storage section  173 - 1  stores, as shown in  FIG. 7 , a state table in which the state information item representing “available” and “busy” are matched to the IP addresses IPN IF 12 - 1 ,  17 - 1  to  17 - j.    
      When an incoming call arrives from the IP network IPN and the speech circuits are all busy, the control section  172 - 1  forwards the incoming call to the IPN IF 12 - 1  whose speech circuit is available, that is, forwards the incoming call based on the state table stored in the storage section  173 - 1 .  
      An explanation will be made below about the operation of the IP telephone system thus structured.  
      The control section  172 - 1  of the IPN IF 17 - 1  performs control processing as shown in  FIG. 8 . That is, the control section  172 - 1  monitors whether or not all the speech circuits in the speech processing section  171 - 1  are busy (step ST 8   a ) and if Yes, transmits the state information items and self IP addresses representing “busy” to the other IPN IF&#39;s  17 - 2  to  17 - j  through a control bus  16  (step ST 8   b ). After this, the control circuit  172 - 1  decides whether or not any speech circuit is available (step ST 8   c ). If Yes, control goes to step ST 8   b  for processing.  
      On the other hand, the control section  172 - 2  of the IPN IF 17 - 2  performs control processing as shown in  FIG. 9 . That is, when the IP address and state information item are notified from IPN IF 17 - 1  (step ST 9   a ), the control section updates the state information item corresponding to the IPN IF 17 - 1  in the state table stored in the storage section  173 - 1  (step ST 9   b ).  
      According to the second embodiment thus structured, the storage sections  173 - 1  to  173 - j  for storing the state table are provided in the IPN IF 17 - 1  to  17 - j  and, based on the state table, the control sections  172 - 1  to  172 - j  decide any available speech circuit for the respective IPN IF&#39;s  12 - 1  and  17 - 1  to  17 - j . Since an incoming call is directly forwarded to, for example, the IPN IF 17 - 2  having any available speech circuit, it is possible to perform proper and rapid connection processing in a simpler procedure.  
      Further, according to the second embodiment, the state table of the storage section  173 - 1  to  173 - j  can be automatically updated to the newest information at all times without any manual updating operation by the maintenance managing personnel on the main apparatus  1 B.  
     Third Embodiment  
       FIG. 10  is a view showing a schematic arrangement of an IP telephone system according to a third embodiment of the present invention. In  FIG. 10 , an explanation will be made below with the use of the same reference numerals employed to designate parts or elements corresponding to those shown in  FIG. 1 .  
      A signaling section (call controller)  11  of a main apparatus  1 C includes a state deciding section  111  and a formal destination updating section  112 . The state deciding section  111  decides whether or not there exists any available speech circuit in the IPN IF&#39;s  12 - 1  to  12 - n.    
      Based on a result of the decision by the state deciding section  111 , the forward destination updating section  112  is so operated as to, where all forward destination speech circuits in the IPN IF&#39;s  12 - 1  to  12 - n  are “engaged”, designate the IPN IF&#39;s  12 - 3  which has an available speech circuit as a now forward destination and update the forward designation table of the control sections  122 - 1  to  122 - n.    
      According to the above-mentioned third embodiment, the forward destination tables of the respective control sections  122 - 1  to  122 - n  are updated based on the in-use state of the speech circuit in the IPN IF&#39;s  12 - 1  to  12 - n  controlled by the signaling section  11 . Since, therefore, any call is not forwarded to all busy IPN IF&#39;s  12 - 1  to  12 - n  from the outset and it is possible to make rapid and proper connection processing an hence to alleviate the processing burden of the respective IPN IF&#39;s  12 - 1  to  12 - n.    
     Fourth Embodiment  
       FIG. 11  is a view showing a schematic arrangement of an IP telephone system according to a fourth embodiment of the present invention. In  FIG. 11 , the same reference numerals are employed to designate parts or elements corresponding to those shown in  FIG. 1 .  
      A main apparatus ID includes an IPN interfaces  18 - 1  to  18 - n  (hereinafter referred to as IPN IF&#39;s  18 - 1  to  18 - n ). The IPN IF&#39;s  18 - 1  to  18 - n  include speech processing sections  181 - 1  to  181 - n , control sections  182 - 1  to  182 - n  and forward repeated number adding sections  183 - 1  to  183 - n  (hereinafter referred to as adding sections  183 - 1  to  183 - n ). Here, an explanation of it will be made below using IPN IF 18 - 1  as a representative example.  
      The adding section  183 - 1  adds “1” as forward repeated number information to an incoming call to be forwarded to another IPN IF 182 - 2 . At the time of receiving the incoming call, the control section  182 - 1  decides whether or not the forward repeated number information is above a predetermined value and, if so, the forwarding of the incoming call is stopped.  
      The operation of the IP telephone system thus structured will be explained below.  
      The control section  182 - 1  of the IPN IF 18 - 1  performs control processing as shown in  FIG. 12 . That is, the control section monitors whether or not any incoming call is received (step ST 12   a ) and, if Yes, decides whether or not there exists any available speech circuit (step ST 12   b ). If Yes, the control section performs incoming call processing with the use of the available circuit (step ST 12   c ).  
      If No, the control section  182 - 1  decides whether or not any forward repeated number information is added to the incoming call and, if the forward repeated number information is added to the incoming call, decides whether or not the forward number is above a predetermined value (step ST 12   d ). If Yes, the control section  182 - 1  stops the incoming call forward processing and notifies the caller to the effect that re-connect operation will be made (step ST 12   e ).  
      If, on the other hand, the forward repeated number is less than the predetermined value (No), the control section  182 - 1  forwards the incoming call to the adding section  183 - 1  where the forward repeated number information (+1) is added to the incoming call (step ST 12   f ). The resultant incoming call is forwarded to another IPN  18 - 2  through the control bus  16  (step ST 12   g ). Incidentally, the forward repeated number information may be forwarded, by way of the IP network IPN, with a control message (SETUP) added thereto.  
      In the above-mentioned fourth embodiment, the adding sections  183 - 1  to  183 - n  are provided in the IPN IF&#39;s  18 - 1  to  18 - n  and, where any control sections  182 - 1  to  182 - n  decide that the forward repeated number added to the incoming call is above the predetermined value, the control section notifies the caller side to make re-connection again, so that it is possible to automatically step the forward processing on an elapsed-time old incoming call.  
      Thus, the caller side grasps the rejection of his or her call as an incoming call to the destination side and can make any prompt and proper re-connection operation, etc. Further, the main apparatus ID on the incoming call side can make the next incoming call processing promptly.  
     Fifth Embodiment  
       FIG. 13  is a view showing a schematic arrangement of an IP telephone system according to a fifth embodiment of the present invention. In  FIG. 13 , VG 1  to VGk represent voice gateways; T 11  to T 1   m  and T 21  to T 2 P, terminal devices; and VM 1  to VMq, voice mail devices. The voice gateways VG 1  to VGk are connected through an IP network IPN. Further, the terminal devices T 11  to T 1   m  and T 21  to T 2 P, and voice mail devices VM 1  to VMq, respectively, constitute extension groups.  
      The voice gateway VG 1  makes a connection between the IP network IPN and the terminal devices T 11  to T 1   m  and has communication protocol and signal format conversion functions between the IP network IPN and the terminals T 11  to T 1   m.    
      The voice gateway VG 2  makes a connection between the IP network IPN and the terminal devices T 21  to T 2 P and has communication protocol and signal format conversion functions between the IP network IPN and the terminal devices T 21  to T 2 P.  
      The voice gateway VGk makes a connection between the IP network IPN and the voice mail devices VM 1  to VMq and has the communication protocol and signal format conversion functions between the IP network IPN and the voice mail devices VM 1  to VMq.  
      Further, the voice gateway VG 1  has a management table for managing the state of an analog circuit line port and has the function of deciding whether or not there exists any available analog circuit line port when an incoming call reaches a destination terminal device T 11  from the IP network IPN. The voice gateway VG 1  has the function of forwarding an incoming call to the voice gateway VG 2  by way of the IP network IPN if, of all the analog circuit line ports, none of them is available.  
      The voice gateway VG 2  has a management table for managing the states of the analog circuit line ports and decides whether or not there exist any available analog circuit line port when an incoming call is received. This gateway creates, when there exists no available analog circuit line port, a communication link relative to, for example, the terminal device T 21  with the use of the analog circuit port.  
      According to the above-mentioned fifth embodiment, it is not necessary to provide any gate keeper for managing the operation states of the voice gateways VG 1  to VGk and, when any incoming call to, for example, the terminal device T 11  arrives from the IP network IPN and all the analog circuit line parts in the voice gateway VG 1  are “engaged”, the incoming call is forwarded directly to the voice gateway VG 2  or voice gate VGk. It is, therefore, possible to largely reduce the cost of the system as a whole.  
     Other Embodiments  
      The present invention is not restricted to the above-mentioned embodiments. Although, in the above-mentioned fifth embodiment for example, an explanation has been made in connection with forwarding an incoming call of a destination to the terminal device T 11  onto the voice gateway VG 2  when there is no available analog circuit line port of the voice gateway VG 1 , the present invention is not restricted thereto. By a forward destination table, for example, a forward destination may be fixedly allocated to the voice gateway VGk.  
      In the above-mentioned fifth embodiment, a state data storage section is provided, as in the case of the above-mentioned second embodiment, for storage-managing the in-use states of the analog circuit line ports in the voice gateways VG 1  to VGk and has the function to forward an incoming call based on its storage contents.  
      In the above-mentioned fifth embodiment, a forward repeated number adding function, as well as a function to stop an incoming call forward processing in the case where the forward number of times reaches a predetermined value, may be provided as in the case of the fourth embodiment.  
      Although, in the above-mentioned first embodiment, the forward destination table with a forward source and forward destination set in a one-to-one corresponding relation has been explained as being provided in the respective IPN IF&#39;s  12 - 1  to  12 - n , it may be considered that, depending upon the forward source, a forward destination table is provided in a way to have no forward destination. By doing so, a final forward interface is handled and it is possible to restrict the forwarding number of times.  
      With respect to the kind of system and its structure, the structure of the main apparatus, the kind of terminal device such as a telephone terminal, the kind of communication apparatus such as a voice gateway and its structure, the functional structure of each interface, the incoming call forward processing procedure, and so on, various changes and modifications can be made without departing from the essence of the present invention.  
      Additional advantages an modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.