Patent Publication Number: US-7711267-B2

Title: Remote management of central office operations

Description:
FIELD OF THE INVENTION 
   Implementations consistent with the principles of the invention relate generally to communications networks and, more particularly, to the remote management of central office operations. 
   BACKGROUND OF THE INVENTION 
   A central office typically includes a single manual optical patch panel for managing connections between fiber cables coming into the central office and the routing devices within the central office. If the optical patch panel fails, the central office may become inoperable. 
   Moreover, repair of damaged fibers in a central office implementing a single manual patch panel is a labor intensive process. The repair process often involves sending repair personnel to the central offices at both ends of the damaged fiber. The repair personnel identify the location of the damaged fiber in the manual optical patch panel and then manually connect the damaged fiber to a test device, such as an optical time domain reflectometer, to determine the location of the damage along the fiber. Once the location is identified, a splice crew is sent to the location to repair the damaged fiber. After the fiber has been repaired, the repair personnel at the two central offices remeasure the fiber with the optical time domain reflectometer to determine whether the fiber has been properly repaired. If the fiber has been repaired, the repair personnel manually reconnect the fiber back to its original location in the manual patch panel. This repair process is not only labor intensive, but also prone to errors (e.g., a repair person may mistakenly put the fiber back into a different location in the manual patch panel). 
   SUMMARY OF THE INVENTION 
   In an implementation consistent with the principles of the invention, a method includes detecting that a fiber within a fiber optic cable has failed, and automatically causing a location of a faulty portion of the fiber to be identified in response to the detecting. 
   In another implementation consistent with the principles of the invention, a central office includes a group of first automatic optical patch panels (AOPP). Each AOPP includes a group of optical switches, where each optical switch is operably connected to a single, different optical cable associated with the central office. 
   In a system including an optical patch panel and an optical splitter, a method includes identifying traffic through the optical patch panel to be moved, where the traffic is transmitted over a first fiber; switching the identified traffic through the optical splitter, where the switching causes the traffic to be transmitted over the first fiber and a second fiber; verifying a presence of the traffic on the second fiber; and switching the traffic to the second fiber. 
   In a further implementation consistent with the principles of the invention, a central office includes an optical patch panel operably coupled to an optical fiber and a second optical patch panel configured to couple the first optical patch panel to a test device. The optical fiber is automatically coupled to the test device in response to one or more signals from a remote management device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings, 
       FIG. 1  illustrates an exemplary system in which systems and methods, consistent with the principles of the invention, may be implemented; 
       FIG. 2  illustrates an exemplary configuration of the management device of  FIG. 1  in an implementation consistent with the principles of the invention; 
       FIG. 3  illustrates an exemplary configuration of a central office of  FIG. 1  in an implementation consistent with the principles of the invention; 
       FIG. 4  illustrates an exemplary process for repairing a broken or damaged fiber in an implementation consistent with the principles of the invention; 
       FIGS. 5A-5D  illustrate an exemplary implementation of the processing described in  FIG. 4  in an implementation consistent with the principles of the invention; 
       FIG. 6  illustrates an exemplary process for rolling traffic over from one fiber to another fiber in an optical patch panel in an implementation consistent with the principles of the invention; and 
       FIGS. 7A-7C  illustrate an exemplary implementation of the processing described in  FIG. 6  in an implementation consistent with the principles of the invention. 
   

   DETAILED DESCRIPTION 
   The following detailed description of implementations consistent with the principles of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and their equivalents. 
   Implementations consistent with the principles of the invention provide remote management of central office operations. In one implementation, a central office is provided with automatic optical patch panels (AOPPs) that allow for remote surveillance of the fibers associated with the central office and remote testing of those fibers. In addition, a splitter may be associated with an AOPP to allow for a bridge and roll capability. 
   Exemplary System 
     FIG. 1  illustrates an exemplary system  100  in which systems and methods, consistent with the principles of the invention, may be implemented. As illustrated, system  100  may include a management device  120  that connects to a group of central offices  130 - 1  and  130 - 2  (referred to collectively as “central offices  130 ”) via a network  110 . The number of management devices  120  and central offices  130  illustrated in  FIG. 1  is provided for simplicity. In practice, a typical system could include more or fewer management devices  120  and central offices  130  than illustrated in  FIG. 1 . 
   Network  110  may include a local area network (LAN), a wide area network (WAN), a telephone network, such as the Public Switched Telephone Network (PSTN), an intranet, the Internet, or a combination of these networks or other networks. Management device  120  may include any type of device capable of providing remote surveillance and control of operations at central offices  130 . In one implementation, management device  120  may include one or more devices, such as personal computers, mainframe computers, servers, lap tops, personal digital assistants (PDAs), wireless telephones, etc., threads or processes running on these devices or other types of devices, and/or objects executable by these devices. 
   Central offices  130  may include local telephone company switching centers that receive and direct telephone calls and data transmissions to their appropriate destinations. As described below, central offices  130  may be monitored and remotely tested by management device  120 . As illustrated in  FIG. 1 , central office  130 - 1  may connect to central office  130 - 2  via a cable  140 . In one implementation consistent with the principles of the invention, cable  140  may include a fiber optic cable that includes a group of individual fibers. 
   Management device  120  may connect to network  110  via wired, wireless, and/or optical connections. Similarly, central offices  130  may connect to network  110  via wired, wireless, and/or optical connections. 
   Management Device Configuration 
     FIG. 2  illustrates an exemplary configuration of management device  120  in an implementation consistent with the principles of the invention. As illustrated, management device  120  may include a bus  210 , processing logic  220 , a memory  230 , a read only memory (ROM)  240 , a storage device  250 , an input device  260 , an output device  270 , and a communications interface  280 . It will be appreciated that management device  120  may include other components (not shown) that aid in receiving, transmitting, and/or processing data. 
   Bus  210  may permit communication among the components of management device  120 . Processing logic  220  may include any type of processor or microprocessor that interprets and executes instructions. In other implementations, processing logic  220  may be implemented as or include an application specific integrated circuit (ASIC), field programmable gate array (FPGA), or the like. Memory  230  may include a random access memory (RAM) or another type of dynamic storage device that may store information and instructions for execution by processing logic  220 . ROM may include a conventional ROM device and/or another type of static storage device that may store static information and instructions for processing logic  220 . Storage device  250  may include a type of magnetic or optical recording medium and its corresponding drive for storing information and/or instructions. 
   Input device  260  may include a device that permits an operator to input information to management device  120 , such as a keyboard, a keypad, a mouse, a pen, a microphone, one or more biometric mechanisms, or the like. Output device  270  may include a device that outputs information to the operator, including a display, a printer, a speaker, etc. 
   Communication interface  280  may include any transceiver-like mechanism that enables management device  120  to communicate with other devices and/or systems. For example, communication interface  280  may include mechanisms for communicating with central offices  130  via a network, such as network  110 . 
   As will be described in detail below, management device  120 , consistent with the principles of the invention, may perform remote monitoring and testing of central offices  130 . Management device  120  may perform these and other operations in response to processing logic  220  executing software instructions contained in a computer-readable medium, such as memory  230 . A computer-readable medium may be defined as one or more memory devices and/or carrier waves. The software instructions may be read into memory  230  from another computer-readable medium, such as data storage device  250 , or from another device via communication interface  280 . The software instructions contained in memory  230  may cause processing logic  220  to perform processes that will be described later. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement processes consistent with the principles of the invention. Thus, systems and methods consistent with the principles of the invention are not limited to any specific combination of hardware circuitry and software. 
   Central Office Configuration 
     FIG. 3  illustrates an exemplary configuration of central office  130 - 1  in an implementation consistent with the principles of the invention. It will be appreciated that central office  130 - 2  may be similarly configured. As illustrated, central office  130 - 1  may includes automatic optical patch panels (AOPPs)  310 - 1  through  310 - 3  (referred to collectively as “AOPPs  310 ”), splitters  320 , carrier equipment (CE)  330 , a digital switch  340 , client equipment  350 , and test devices  360 . The number of devices illustrated in  FIG. 3  is provided for simplicity. In practice, a typical central office could include more or fewer AOPPs  310 , splitters  320 , carrier equipment  330 , digital switches  340 , client equipment  350 , and/or test devices  360  than illustrated in  FIG. 3 . Moreover, central office  130 - 1  may include other devices than illustrated in  FIG. 3  that aid in receiving, processing, and/or transmitting signals. 
   AOPPs  310  may include N×M optical switches that receive signals on input ports and switch the signals to the appropriate output ports. In one implementation, AOPPs  310  may, for example, include low-loss photonic switch modules produced by Polatis Ltd., Continuum Photonics, Inc., or other similar types of photonic switch modules. AOPPs  310 - 1  and  310 - 2  switch signals between the individual fibers of a fiber cable, such as cable  140 , and carrier equipment  330 . In one implementation, AOPPs  310 - 1  and  310 - 2  may include one switch for every fiber cable with which central office  130 - 1  is associated. Therefore, if a switch within an AOPP were to fail, the central office  130 - 1  may route traffic around the failed switch. Moreover, since central office  130 - 1  includes multiple AOPPs  130 , the failure of a single AOPP does not render central office  130 - 1  inoperable. Two fiber cables are illustrated as associated with central office  130 - 1  in  FIG. 3  for explanatory purposes only. It will be appreciated that central office  130 - 1  (and AOPPs  130 - 1  and  130 - 2 ) may be associated with more or fewer fiber cables. AOPP  310 - 3  switches signals between AOPPs  310 - 1  and  310 - 2  and test devices  360 . In this manner, AOPP  310 - 3  allows an individual fiber associated with AOPP  310 - 1  or  310 - 2  to be connected to one or more test devices  360  for testing purposes. 
   Splitters  320  may include one or more devices that split a single input optical signal into two identical output optical signals. In one implementation, splitters  320  may include 3 decibel (dB) splitters. As will be described in additional detail below, splitters  320  may provide AOPPs  310 - 1  and  310 - 2  with branch and roll capabilities. 
   Carrier equipment  330  may include devices for formatting signals transmitted between AOPPs  310 - 1  and  310 - 2  and digital switch  340 . In one implementation, carrier equipment  330  may, for example, perform optical-to-electrical conversions, electrical-to-optical conversions, wavelength division multiplexing, etc. Carrier equipment  330  may include bi-directional wavelength division multiplexing (BDWM) and/or ultra long haul (ULH) components. 
   Digital switch  340  may include one or more devices that perform time-division-multiplexed switching of digitized signals. Digital switch  340  may receive signals from client equipment  350  and forward the signals to carrier equipment  330  in a well-known manner. Also, digital switch  340  may receive signals from carrier equipment  330  and forward the signals to other carrier equipment  330  or client equipment  350  in a well-known manner. 
   Client equipment  350  may include one or more transport-type devices. For example, client equipment  350  may include an add-drop multiplexer (ADM), layer  2  switches, Internet Protocol (IP) switches, or the like. 
   Test devices  360  may include one or more devices for testing optical fibers within a cable associated with central office  130 - 1  to determine whether the optical fibers are functioning properly and/or to identify a location of faults within the optical fibers. In one implementation consistent with the principles of the invention, test devices  360  may include, for example, an optical time domain reflectometer (OTDR), an optical spectrum analyzer, a bit error rate tester (BERT), a signal generator, and/or any other equipment that may aid in determining whether the optical fibers are functioning properly and/or to identify a location of faults within the optical fibers. 
   Exemplary Processing 
     FIG. 4  illustrates an exemplary process for repairing a broken or damaged fiber in an implementation consistent with the principles of the invention. Processing may begin with management device  120  ( FIG. 1 ) detecting that a fiber is broken or damaged (act  410 ). Management device  120  may monitor the operating condition of each of the fibers associated with a central office, such as central office  130 - 1 . The lack of a signal on a fiber may be an indication that the fiber has been broken or damaged. In such a situation, an alert may be generated at management device  120  that identifies the problematic fiber. Assume, for explanatory purposes, that the fiber is part of cable  140  that connects central offices  130 - 1  and  130 - 2  ( FIG. 1 ) and that the fiber connects to AOPP  310 - 2  ( FIG. 3 ) in central office  130 - 1  and AOPP  310 -X in central office  130 - 2 . 
   Management device  120  may cause the identified fiber to be connected to a test device  360  (act  420 ). To do so, management device  120  may, for example, send a signal to AOPP  310 - 2  instructing AOPP  310 - 2  to disconnect the fiber from carrier equipment  330  and connect the fiber to AOPP  310 - 3 . Management device  120  may further send a signal to AOPP  310 - 3  instructing AOPP  310 - 3  to connect the fiber to a particular test device  360  (e.g., an optical time domain reflectometer). Similarly, management device  120  may send a signal to AOPPs within central office  130 - 2  to disconnect the fiber from its carrier equipment  330  and connect the fiber to, for example, an optical time domain reflectometer. Management device  120  may send these signals automatically (e.g., in response to the detection of a loss of signal on a fiber) or in response to input from an administrator associated with management device  120 . 
   Test device  360  may then be used to identify the location of the fiber break or damage in a well known manner (act  430 ). For example, by connecting an optical time domain reflectometer to both ends of the fiber (i.e., at central offices  130 - 1  and  130 - 2 ), the location of the break between central office  130 - 1  and  130 - 2  may be identified. Once the location of the break or damage has been identified, a repair crew may be sent to the identified location to repair the fiber. 
   Once the fiber has been repaired, as will be detected by the test devices at central offices  130 - 1  and  130 - 2 , management device  120  may cause the fiber to be disconnected from test devices  360  at central offices  130 - 1  and  130 - 2  and reconnected to the appropriate carrier equipment  330  (act  440 ). For example, management device  120  may send a signal to AOPP  310 - 2  instructing AOPP  310 - 2  to disconnect the fiber from AOPP  310 - 3  and re-connect the fiber to carrier equipment  330 . Management device  120  may send a similar signal to AOPP-X within central office  130 - 2 . 
   The following example illustrates the processing described above with respect to  FIG. 4 . As illustrated in  FIG. 5A , assume that a break has been detected in fiber  2  in cable  140  that connects central office  130 - 1  to central office  130 - 2 . In response, management device  120  may cause fiber  2  to be connected to test devices  360  at central offices  130 - 1  and  130 - 2 , as illustrated in  FIG. 5B . To do so, management device  120  may, for example, send a signal to AOPP  310 - 2  instructing AOPP  310 - 2  to disconnect fiber  2  from carrier equipment  330  and connect fiber  2  to AOPP  310 - 3 . Management device  120  may further send a signal to AOPP  310 - 3  instructing AOPP  310 - 3  to connect fiber  2  to a particular test device  360  (e.g., an optical time domain reflectometer). Similarly, management device  120  may send a signal to AOPP  310 -X within central office  130 - 2  instructing AOPP  310 -X to disconnect fiber  2  from carrier equipment  330  and connect fiber  2  to AOPP  310 -Y. Management device  120  may further send a signal to AOPP  310 -Y instructing AOPP  310 -Y to connect fiber  2  to, for example, an optical time domain reflectometer. 
   The optical time domain reflectometers at central offices  130 - 1  and  130 - 2  may then be used to identify the location of the break in fiber  2 . Once the location of the break has been identified, a repair crew may be sent to the identified location to repair fiber  2 . Prior to or after repair of fiber  2 , it may be desirable to connect other test devices  360  to check, for example, that fiber  2  is operating properly after the repair. In this situation, management device  120  may send a signal to AOPP  310 - 3  instructing AOPP  310 - 3  to disconnect fiber  2  from the first test device  360  and connect it to a second test device  360  (e.g., a bit error rate tester), as illustrated in  FIG. 5C . Similarly, management device  120  may send a signal to AOPP  310 -Y instructing AOPP  310 -Y to disconnect fiber  2  from the first test device  360  and connect it to a second test device  360 . In this way, different tests can be performed on a particular fiber under the control of a remotely-located management device. 
   After fiber  2  has been repaired, as will be detected by the test devices at central offices  130 - 1  and  130 - 2 , and all desired testing has been performed, management device  120  may cause fiber  2  to be disconnected from test devices  360  at central offices  130 - 1  and  130 - 2  and reconnected to the appropriate carrier equipment  330 , as illustrated in  FIG. 5D . For example, management device  120  may send a signal to AOPP  310 - 2  instructing AOPP  310 - 2  to disconnect fiber  2  from AOPP  310 - 3  and re-connect the fiber to carrier equipment  330 . Similarly, management device  120  may send a signal to AOPP  310 -X instructing AOPP  310 -X to disconnect fiber  2  from AOPP  310 -Y and re-connect the fiber to carrier equipment  330 . The ability to control testing of fibers at central offices  130  via a remote management device  120  greatly reduces the man power required by conventional testing and repair techniques. 
     FIG. 6  illustrates an exemplary process for rolling traffic over from one fiber (referred to herein as the “current fiber”) to another fiber (referred to herein as the “new fiber”) in a central office in an implementation consistent with the principles of the invention. Processing may begin by identifying traffic to be moved (act  610 ). For example, if maintenance is to be performed on the current fiber within a cable, it may be necessary to move the traffic on that fiber to a new fiber within the cable. In this way, traffic will not be interrupted during the maintenance activity performed on the current fiber. 
   Once the traffic has been identified, the traffic can be switched through a splitter, such as splitter  320  ( FIG. 3 ) and bridged to both the current fiber and the new fiber (act  620 ). As a result, the current fiber and the new fiber will have the same signal on them. 
   The receive end of the new fiber may be checked to verify that the signal is received on that fiber (act  630 ). The receive end of the new fiber refers to the end of the new fiber at the destination central office. The traffic from the current fiber may be rolled to the new fiber (act  630 ) and the maintenance on the current fiber may be performed. If desirable, after the maintenance has been performed on the current fiber, the traffic from the new fiber may be rolled back to the current fiber in a manner similar to that described above. 
   The following example illustrates the processing described above with respect to  FIG. 6 . As illustrated in  FIG. 7A , traffic is patched through AOPP  310 - 2  from the fiber connected to port  710  of AOPP  310 - 2  to the output fiber connected to port  720 . Due to maintenance reasons, for example, the traffic exiting on the fiber connected to port  720  needs to be moved to another fiber, such as the fiber connected to output port  730  in the example illustrated in  FIG. 7A . 
   To roll the traffic over to the new fiber, the traffic on input port  710  of AOPP  310 - 2  may be switched to the port connected to splitter  320  (i.e., port  740 ), which causes the traffic to be bridged to input ports  750  and  760  of AOPP  310 - 2 , as illustrated in  FIG. 7B . Input port  750 , which is connected to an output of splitter  320 , may be switched to input port  720  (i.e., the current output port). Also, input port  760 , which is connected to another output of splitter  320 , may be switched to output port  730  (i.e., the new output port). At this time, the fibers connected to both output port  720  and output port  730  have the same traffic on them. 
   The receive end of the fiber connected to output port  730  may be checked to verify that the signal is present. If the signal is present, indicating that that fiber is operating properly, input port  710  may be switched to output port  730  such that all traffic from input port  710  is only transmitted from output port  730 , as illustrated in  FIG. 7C . In one implementation consistent with the principles of the invention, management device  120  may instruct central office  130 - 1  to perform this branch and roll operation. 
   CONCLUSION 
   Implementations consistent with the principles of the invention provide remote management of central office operations. In one implementation, a central office is provided with automatic optical patch panels AOPPs that allow for remote surveillance of the fibers associated with the central office and remote testing of those fibers. In one implementation, each cable with which the central office is associated is connected to an individual switch. In this way, failure of a switch does not render the entire central office inoperable. In addition, a splitter may be associated with an AOPP to allow for a bridge and roll capability. 
   The foregoing description of exemplary implementations of the invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. For example, while the above description focused on a remotely located management device  120  controlling operations of a central office, implementations consistent with the invention are not so limited. In other implementations, management device  120  may be located within one or more central offices. 
   While series of acts have been described with respect to  FIGS. 4 and 6 , the order of the acts may be varied in other implementations consistent with the invention. Moreover, non-dependent acts may be implemented in parallel. 
   It will be apparent to one of ordinary skill in the art that aspects of the invention, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement aspects consistent with the principles of the invention is not limiting of the invention. Thus, the operation and behavior of the aspects of the invention were described without reference to the specific software code—it being understood that one of ordinary skill in the art would be able to design software and control hardware to implement the aspects based on the description herein. 
   Further, certain portions of the invention may be implemented as “logic” that performs one or more functions. This logic may include hardware, such as an application specific integrated circuit or a field programmable gate array, software, or a combination of hardware and software. 
   No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.