Abstract:
Methods and apparatuses for reducing connection interference within and across adjacent interfaces are provided. An interface includes ports arranged along at least a first axis and second axis. The ports on the first axis are offset from the ports on the second axis. When two interfaces are provided adjacent to each other, the ports on the last axis of the first circuit board are offset from the ports on the first axis of the second circuit board.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/316,554 (“the &#39;554 Application”), which was filed on Mar. 23, 2010, and entitled “A Connector Arrangement for High-Density Input/Output Connectivity into a Network Node.” The &#39;554 Application is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure is related to port configurations for network equipment. 
       BACKGROUND 
       [0003]    A Data-Over-Cable Service Interface Specification (DOCSIS) system, for example, can be used to deliver high-definition digital entertainment and telecommunications such as video, voice, and high-speed Internet to subscribers over an existing cable television network. The cable television network can take the form of an all-coax, all-fiber, or hybrid fiber/coax (HFC) network. A cable service provider, such as a multiple service operator (MSO), can deliver these services to subscribers by using a cable modem termination system (CMTS) located at a headend and cable modems (CMs) and customer premise equipment (CPE) devices, such as set-top boxes, multimedia terminal adapters (MTAs), and gateway devices, located at subscriber premises. 
         [0004]    As more traffic is transmitted between the CMTS and CMs due to, for example, an increase in the data rates demanded by CMs served by the network and/or delivery of expanded services such as video-on-demand, there is a need to increase the number of input and output ports in the CMTS to deliver and receive such traffic. A CMTS can include one or more interface cards that serve as RF interfaces between the headend and CMs. Each interface card can have multiple ports for upstream and downstream traffic. As traffic increases between the CMTS and CMs, the service provider can increase the number of ports in the CMTS by adding new line cards and/or by increasing the number of ports in one or more interface cards. Due to space constraints, for example, increasing the number of interface cards may not be a desirable option. Accordingly, equipment vendors are supplying interface cards with more ports. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a block diagram illustrating an example DOCSIS-based system used to provide communications between a CMTS and a CM over a network. 
           [0006]      FIG. 2  is a block diagram illustrating an example RF interface portion of the back-side of a CMTS which includes one or more interface cards. 
           [0007]      FIG. 3  illustrates an example port arrangement for an interface card. 
           [0008]      FIG. 4A  illustrates the port offset between interface cards achieved by using interface cards having two different port configurations. 
           [0009]      FIG. 4B  illustrates the port offset between the interface cards achieved by using the same port configuration but staggering the interface cards. 
           [0010]      FIG. 5  illustrates an example two axis port configuration. 
           [0011]      FIG. 6A  illustrates the space between ports across interface cards having the port configuration of  FIG. 3 . 
           [0012]      FIG. 6B  illustrates the space between ports across interface cards having the two axis port configuration of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Various implementations of this disclosure can operate to reduce connection interference within and across adjacent interfaces having ports arranged on a plurality of axes by offsetting the ports on one axis from the ports on an adjacent axis. 
         [0014]    Although this disclosure makes reference to a DOCSIS-based system and CMTSs, this disclosure is not intended to be limited to a DOCSIS-based system or CMTS. This disclosure can be applied to other communication systems including wired or wireless systems. This disclosure also can be applied to any network node or network equipment including routers, switches, servers, DSL equipment, passive optical network (PON) equipment such as optical line terminals (OLT), etc., or any other equipment, including stand-alone equipment. 
         [0015]      FIG. 1  illustrates an example DOCSIS-based system operable to deliver high-definition digital entertainment and telecommunications such as video, voice, and high-speed Internet to a subscriber over an existing cable television network. As shown in  FIG. 1 , traffic (e.g., data, video, and voice signal) can be transferred over a cable network  130  between a CMTS  110  or converged edge router (CER) and a CM  120 . The cable network  130  can take the form of an all-coax, all-fiber, or hybrid fiber/coax (HFC) network. 
         [0016]      FIG. 2  illustrates an example RF interface portion of the back-side of a CMTS  110 . The RF interface portion of the CMTS  110  can include one or more interface cards  205 ( 1 ),  205 ( 2 ), . . .  205 ( n ) that serve as RF interfaces between the headend and CMs. Each interface card  205 ( i) , i=1, . . . n, can have a plurality of ports  205 ( i   j ), j= 1, . . . m, arranged on a panel or face plate for upstream and downstream traffic. As discussed above, as traffic increases between the CMTS/CER 110 and CMs, the service provider can increase the number of ports in the CMTS 110 by adding new interface cards and/or by increasing the number of ports of one or more interface cards. As discussed above, increasing the number of interface cards may not be a desirable option, therefore, equipment vendors are supplying interface cards with more ports.    
         [0017]    Interface cards with an increased number of ports can be achieved by reducing the space  210  between ports to fit more ports on the interface card. The ports can be arranged on a single axis  215  (e.g. a horizontal or vertical axis, depending on the orientation of the interface card) as shown in  FIG. 2 . 
         [0018]    Alternatively, as shown in  FIG. 3 , the ports on an interface card, for example the i-th interface card  205 ( i ) of  FIG. 2 , can be arranged on two parallel axes  215 ( 1   i ),  215 ( 2   i ). For this disclosure,  205 ( i   j   , k ) represents the j-th port on the k-th axis of the i-th interface card. Each port  205 ( i   j ,  1 ), j=1, . . . m′ on the first axis of the i-th interface card  215 ( 1   i ) is aligned with the corresponding port  205 ( i   j ,  2 ), j=1, . . . m′, respectively, on the second axis  215 ( 2   i ). That is, for each port  205 ( i   j ,  1 ), j=1, . . . m′ on the first axis  215 ( 1   i ) and the corresponding port  205 ( i   j ,  2 ), j=1, . . . m′, respectively, on the second axis  215 ( 2   i ), an axis  220 ( j ), j=1, . . . m′, that is perpendicular to the first and second axes  215 ( 1   i ),  215 ( 2   i ) and passing through the port can be drawn. 
         [0019]    As equipment vendors attempt to increase the number of ports on an interface card, the space between the ports can become too small to easily insert, connect, disconnect, or remove a connector. Furthermore, as connections (e.g., connectors and/or cables) are attached to the ports on the interface card, it can become increasingly difficult to insert, connect, disconnect, or remove connectors due to the added interference from the connections. This interference can be referred to as intra-card connection interference. 
         [0020]    Inter-card connection interference can also occur. That is, referring to  FIG. 2 , the ports on one interface card (e.g., interface card  205 ( 1 )) and/or the connections to the ports on the interface card can interfere with inserting, connecting, disconnecting, or removing connectors to ports on an adjacent interface card (e.g., interface card  205 ( 2 )). 
         [0021]    For interface cards having ports arranged on a single axis, U.S. Pat. No. 6,457,978, , entitled “Method And Apparatus For Arranging Cable Connectors To Allow For Easier Cable Installation,” which was issued on Oct. 1, 2002, and is incorporated herein by reference in its entirety, addresses inter-card connection interference. Referring to  FIG. 4A , the &#39;978 Patent discloses using two different interface cards  405   a ,  405   b  where the ports on the first interface card  405   a  are offset from the ports on the second interface card  405   b . When the two interface cards  405   a ,  405   b  are inserted adjacent to one another, the ports on the first interface card are staggered/offset from the ports on the second interface card thereby increasing the space  255  (see  FIG. 2 ) between ports across interface cards. Thus, the space  455  between ports across the interface cards  405   a ,  405   b  can be greater than the space  255  between ports across the interface card  205 ( 1 ),  205 ( 2 ). Referring to  FIG. 4B , the &#39;978 Patent discloses in an alternate embodiment using identical interface cards, instead of using two different interface cards, to achieve port offset between the interface cards by staggering the interface cards. 
         [0022]    However, the &#39;978 patent does not address intra-card connection interference. Further, the &#39;978 patent does not address intra- and inter-card connection interference for interface cards having ports arranged on a plurality of axes. 
         [0023]      FIG. 5  illustrates an example two axis port configuration that can reduce intra- and inter-card connection interference. For the purpose of illustration, assume the total number of ports on each interface card of  FIGS. 2 ,  3 , and  FIG. 5  equals 8 (i.e., m=8 and m′=4). As shown in  FIG. 5 , the ports on an i-th interface card  505 ( i ) can be arranged on two parallel axes  515 ( 1   i ),  515 ( 2   i ). The ports  505 ( i   j ,  1 ), j=1, . . . m′ on the first axis  515 ( 1   i ) are staggered/offset from the ports  505 ( i   j ,  2 ), j=1, . . . m′ on the second axis  515 ( 2   i ) to provide more free space around the ports thereby reducing intra-card connection interference. That is, for each port  505 ( i   j ,  1 ), j = 1 , . . . m′ on the first axis  515 ( 1   i ) and the corresponding port  505 ( i   j ,  2 ), j=1, . . . m′, respectively, on the second axis  515 ( 2   i ), if an axis  520 ( j ), j=1, . . . m′, respectively, was drawn that passes through the ports, the axis would be rotated a certain number of degrees, θ j , j=1, . . . m′, respectively, from an axis  530 ( j ) j=1, . . . m′, respectively, extending perpendicular from the first or second axis  515 ( 1   i ),  515 ( 2   i ). Thus, with this configuration, the amount of free space around the ports of the interface card of  FIG. 5  can be greater than the amount of free space around the ports of the interface cards of  FIG. 2  and  FIG. 3 . 
         [0024]    Although  FIG. 5  illustrates four ports for each axis (i.e., m′=4), more are less ports can be included on each axis by, for example, decreasing or increasing the vertical distance  540  between ports. Assuming the orientation of the interface card as shown in  FIG. 5 , in some implementations, the vertical distance (e.g., vertical distance  540 ) between each port and the horizontal distance (e.g., horizontal distance  545 ) can be equal. In some implementations the vertical distance between each port is greater than the horizontal distance between each port. In some implementations, the vertical distance between each port is less than the horizontal distance between each port. In some implementations, θ j =θ, j=1, . . . m′. In some implementation θ j , j=1, . . . m′ can vary. In some implementations, only a portion of an interface card is configured in the two axis port configuration illustrated in  FIG. 5 . 
         [0025]    In some implementations, there can be varying vertical distances between ports in a single interface card. 
         [0026]      FIG. 6B  illustrates how the two axis port configuration of  FIG. 5  can increase the amount of free space around the ports across interface cards thereby reducing inter-card connection interference. For the purpose of illustration, assume the total number of ports on each interface card of  FIGS. 2 ,  6 A,  6 B equals 16 (i.e., m=16, m′=8). When a first interface card  505 ( 1 ) is placed adjacent to a second interface card  505 ( 2 ), the ports  505 ( 2   j ,  1 ), j=1, . . . m′ on the first axis  515 ( 1   2 ) of the second interface card  505 ( 2 ) will be staggered/offset from the ports  505 ( 1   j ,  2 ), j=1, . . . m′, respectively, on the second axis  515 ( 2   1 ) of the first interface card  505 ( 1 ). Thus, the amount of free space around the ports  505 ( 1   j ,  2 ) and  505 ( 2   j ,  1 ), j=1, . . . m′ can be greater than the amount of free space around the ports  605 ( 1   j ,  2 ) and  605 ( 2   j ,  1 ), j=1, . . . m′ of  FIG. 6A  and can be greater than the amount of free space around the ports across the interface cards of  FIG. 2 . 
         [0027]    The two axis port configuration of  FIG. 5  offers one or more advantages over the prior art arrangements. First, only a single port configuration is needed to reduce inter-card connection interference. Second, the interface cards do not need to be staggered to achieve port offset between interface cards. 
         [0028]    In some implementations, the ports on the interface cards can be arranged in a staggered fashion on three or more parallel axes. 
         [0029]    While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular implementations of particular inventions. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.