Abstract:
A telephone system which has the ability to detect when a handset is connected to a local loop telephone line. The system does not allocate any significant amount of resources to handle calls on a particular local loop until it detects that a handset is connected to the local loop line. When the system is installed in a wiring closet the lines to each of the local loops in the building or office suite can be connected to the system. When handsets are connected to particular local loops, the system allocates resources to the particular local loop.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to telephone equipment and more particularly to the installation and activation of telephone equipment.  
         BACKGROUND OF THE INVENTION  
         [0002]    U.S. Pat. No. 6,108,346 which was issued Aug. 22, 2000 and co-pending patent application Ser. No. 09/527,968 filed Mar. 17, 2000 entitled “Integrated Scalable PBX and Router with Pooling” describe an integrated system that provides the functions of both a telephone PBX and an Ethernet data router. The system shown in the above cited references has both ports that provide connect to local loop telephone lines and ports that connect to Ethernet cables.  
           [0003]    Telephone systems and routers for Ethernet cables are typically installed in a building&#39;s of office suite&#39;s wiring closet. In many instances at least two unshielded twisted pairs of wires (UTP) cables (i.e. a telephone cable and an Ethernet cable) extend from the wiring closet to each office in the building or office suite. An office typically includes a computer connected to the Ethernet cable and a telephone is connected to the telephone cable.  
           [0004]    The Ethernet protocol has a facility whereby units connected to an Ethernet LAN can notify other units on the LAN of their presence. Thus if one end of an Ethernet cable is connected to a router, when a computer is connected to the other end of the cable, the computer will notify the router of its presence on the LAN. A router need not allocate any significant amount of resources to handle a particular port until the router is notified that a unit is connected to that port. It is wasteful to assign resources to a port when no devices are connected to that port.  
         SUMMARY OF THE PRESENT INVENTION  
         [0005]    The present invention provides a telephone system which has the ability to detect when a handset is connected to a local loop telephone line. The system does not allocate any significant amount of resources to handle calls on a particular local loop until it detects that a handset is connected to the local loop line. When the system is installed in a wiring closet the lines to each of the local loops in the building or office suite can be connected to the system. When handsets are connected to particular local loops, the system allocates resources to the particular local loop. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0006]    [0006]FIG. 1 illustrates an office suite with a wiring closet and lines going from the wiring closet to the offices.  
         [0007]    [0007]FIG. 2 illustrates a system that has resources that are allocated to handle calls on local loop lines.  
         [0008]    [0008]FIG. 3 is a circuit for detecting if a handset is connected to a local loop.  
         [0009]    [0009]FIG. 4 is a flow diagram of the operation of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0010]    A typical office suite  100  is illustrated in FIG. 1. The suite includes a conventional wiring closet  101  and offices  102 A to  102   x.  The arrow between offices  102 C and  102   x  indicates that there can be any number of offices as appropriate for a particular office suite. It is noted that in FIG. 1, the physical size of the offices  102 A to  102   x  relatives to the size of the wiring closet  101  is not to scale. The actual size of the offices and the wiring closet is as is conventional.  
         [0011]    There is an Ethernet cable (for example  106   x  shown by the solid line) and a telephone cable (for example  107   x  shown by the dotted line) between each office and the wiring closet  101 . The lines from wiring cabinet  101  to offices  102 A to  102   x  are designated  107 A to  107   x.  All of the lines are collectively referred to as lines  107 . Each of these lines is a conventional UTP (unshielded twisted pair) cable. Each telephone cable has two physical wires and each Ethernet cable has four physical wires. Thus, there is both a LAN (local area network) connection and a conventional telephone connection between the wiring closet and each office  102 A to  102   x.  It is noted that there may be other connections to the wiring cabinet  101  such as lines the outside telephone network and to various outside computer networks. These are not shown in FIG. 1 since they are not particularly relevant to the present invention.  
         [0012]    A combined telephone switch and Ethernet router  111  is located in wiring closet  101 . The combined telephone switch and Ethernet router  111  may be the type of unit shown in U.S. Pat. No. 6,108,346 which was issued Aug, 22, 2000 or in co-pending patent application Ser. No. 09/527,968 filed Mar. 17, 2000 entitled “Integrated Scalable PBX and Router with Pooling”. This application and patent here hereby incorporated herein by reference.  
         [0013]    The telephone lines from offices  102 A to  102   x  are terminated at posts on terminal block  105 T located in wiring closet  101 . The Ethernet lines from offices  102 Ato  102   x  are terminated at posts on a terminal block  105 E located in wiring closet  101 . (It is noted that the posts on terminal blocks  105 E and  105 T are not specifically shown in the drawings). Terminal blocks  105 E and  105 T are conventional commercially available terminal blocks. All the post on the terminal blocks  105 T and  105 E are connected to the combined telephone switch and Ethernet router  111 .  
         [0014]    Some of the lines  107  have telephone handsets connected to them in offices  102 A to  102   x.  Other offices do not have handsets connected to line  107  that goes to that particular office. As explained below, the present invention provides a mechanism whereby telephone switch and Ethernet router  111  can detect which offices have telephone handsets connected to line  107  that goes to the office and which offices do not have handsets connected to line  107  connected to that office. Each of the lines  107  which has a telephone handset connected to it utilizes some resources  111 B in telephone switch and Ethernet router  111 . Resource  111 B could for example be memory which must be allocated to handle calls on a particular line. Allocation of resources to service particular lines is conventional in computerized PBX systems. As an extreme example, if none of the offices  102 A to  102   x  have telephone handsets connected to lines  107 , the telephone switch and Ethernet router  111  would have to allocate none of the resource  111 B to handling calls on the telephone lines and this resource could be assigned to other tasks such as handling Ethernet packets.  
         [0015]    A presence detection circuit  111 A interfaces the lines from terminal block  105 T to telephone switch and Ethernet router  111 . The present detector circuit  11 A is shown in more detail in FIG. 2. It should be understood that each of the Ethernet cables  106  consists of four physical wires and each of the telephone cables  107  consist of two physical wires. In FIG. 2 these two wires in a representative telephone cable are designated 107×1 and 107×2. The presence detector consists of a power supply  201 , a signal detector  202  and a switch  203 . The power supply  201  and the current detector  202  are periodically connected to each pair of telephone lines  107 .  
         [0016]    The power supply applies an AC voltage to the lines and if the signal detector detects the AC signal it indicates that a telephone handset is connected to the other end of the lines. As an example, an AC voltage in the range of 5 to 10 volts and 1000 cycles per second could be used. Note that when a handset is connected to telephone lines, the ring circuit provides a path for an AC signal. If a handset is not connected to the lines, there is an open circuit and no current can flow. If the signal detector  202  determines that there is a telephone connected to the line, resources  111 B are allocated to that particular line. A conventional switch  203  (not explicitly shown in FIG. 2) sequentially connects the power supply  201  and the current sensor  202  to each of the telephone lines  107 A to  107   x  in sequence.  
         [0017]    If the present detector  111 A detects that there is telephone handset connected to a particular line  107 , a portion of resource  111 B is allocated to this particular line  107 . The resources allocated could, for example, be some memory that is allocated to handling calls to and from this line.  
         [0018]    [0018]FIG. 3 illustrates the portion of system  111  that allocates resources to handle calls. Memory  111 B provides memory for many function in system  111 . For example it provides memory for the operating system and it provides memory that is uses to service each of the active telephone lines connected to the system. Data base  302  contains information indicating which telephone lines have handsets connected to the lines. Data base  302  is updated by the presence detector  111 A. Memory allocation Unit  303  allocates a portion of memory  111 B to each telephone line which has a handset connected thereto. Among other functions the memory allocated to each line serves as a memory buffer for data from the associated line.  
         [0019]    The present invention greatly facilitates installing a telephone and Ethernet switch in a suite of offices. FIG. 4 illustrates the process of the present invention. First, as indicated by block  401 , the Telephone Switch and Ethernet router  111  is installed in the wiring closet  101 . Next as indicated by block  402  all the lines on terminal blocks  105 E and  105 T are connected to the unit  111 . The Telephone Switch  111  then detects which lines  107  have handsets connected to them as indicaterd by block  403 . For those lines that do have handsets connected, and only for those lines, a portion of resource  111 B is allocated as indicated by block  404 .  
         [0020]    The result is that only those lines with handsets utilize a portion of resource  111 B. Thus, the technician installing unit  111  need not spend time determining which lines have handsets connected. The technician merely connects all of the telephone lines to unit  111  and unit  11  detects and allocates resources to those lines that have handsets connected to them.  
         [0021]    The present invention also facilitates identifying telephone lines which are defective. If a technician knows that a hand set is connected to a particular pair of lines and the system shows no handset connected, it indicates that the lines are defective.  
         [0022]    It is noted that the Telephone Switch and Ethernet router  11  uses the inherent properties of an Ethernet protocol to determine which Ethernet lines have computers connected thereto. Resources are only allocated to those Ethernet lines that have computers connected thereto. While the embodiment of the invention described above utilizes a combined Telephone Switch and Ethernet router, the invention could also be applied to a standalone telephone PBX.  
         [0023]    While a preferred embodiment of the invention has been shown and described, it should be understood that various changes in form and detail can be made without departing from the spirit and scope of the invention. The scope of the invention is limited only by the scope of the appended claims.