Abstract:
Systems and methods for detecting power outages in communication networks are described. In one implementation, an alarm associated with a network error is detected. Attempts are made to contact the network equipment originating the alarm. The alarm is linked to an error that is identified as either a power outage or another type of error depending on the results of the attempts to contact the network equipment originating the alarm.

Description:
BACKGROUND 
   The present invention relates to communication network management. In particular, but not by way of limitation, the present invention relates to a system and method for error detection in a communication network. 
   Communication networks require quick and reliable error detection and isolation to ensure network integrity, and maintain both customer satisfaction and customer loyalty. In the competitive telecommunications industry it is advantageous to identify network troubles quickly and get them resolved as soon as possible. 
   Previously known T3 and T1 technology has limited automation for diagnosing errors in T3 and T1 network equipment, especially errors due to power outages. As an example,  FIG. 1  shows a block diagram  100  of a previously known power outage detection and isolation system. System  100  consists of a customer premises equipment (CPE)  110 , a channel service unit (CSU)  120 , an alarm management platform  130 , a test tool  140 , a ticketing system  160 , a maintenance platform  170 , a work center  180  and a customer  190 . 
   In this system, if the CPE  110  experiences a power outage the alarm management platform  150  detects an alarm  112  and alerts the ticketing system  160 . The ticketing system  160  forwards a notification (not shown) of the alarm  112  to the work center  160 . The work center  160  uses the test tool  140  to contact the CPE  110  or the CSU  120  in order to diagnose the alarm  112 . The alarm  112  is identified as either a power outage or another type of error by the work center  160 , and the customer  190  is contacted to confirm the identification. 
   A disadvantage of previously known systems like that described with respect to  FIG. 1  is their reliance on the one or more technicians to properly and quickly identify an outage alarm. The use of technicians is prone to human error and the time required to diagnosis an out of service state is limited by technician response time. 
   Accordingly, current automated techniques for detecting and isolating errors in T1, T3, and other communication networks do not operate in a convenient, cost-effective manner and will most certainly not be satisfactory in the future. There is a need for real-time monitoring of the entire communication path from customer installation to customer installation that provides a proactive method for trouble detection and isolation in the communication network. 
   SUMMARY OF THE INVENTION 
   Embodiments of the present invention include methods for detecting and isolating errors in a communication network. In one embodiment the invention may be characterized as a method for automatically detecting a power outage in a communication network. The method includes detecting an existence of an error, identifying a device in the communication network that created the error, and determining whether the error is a power outage. 
   Exemplary embodiments of the present invention are more fully described in the Detailed Description section. It is to be understood, however, that there is no intention to limit the invention to the forms described in either this section or in the Detailed Description section of this application. One skilled in the art can recognize that there are numerous modifications, equivalents and alternative constructions that fall within the spirit and scope of the invention as expressed in the claims 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various advantages and a more complete understanding of the present invention are apparent and more readily appreciated by reference to the following Detailed Description and to the appended claims when taken in conjunction with the accompanying Drawings wherein: 
       FIG. 1  illustrates a block diagram of an outage detection system known in the art; 
       FIG. 2  illustrates a block diagram of a customer-to-customer communication network system in accordance with an exemplary embodiment of the present invention; and 
       FIG. 3  depicts a process flow diagram representative of operation of the exemplary embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   The present arrangement described below allows a service provider to detect and isolate troubles in a communication network. Although specific examples are developed using T1 and/or T3 network technologies, one of ordinary skill in the art will recognize that alternative network technologies are within the scope of the present invention. 
     FIG. 2  is a communication network  200  in accordance with an exemplary embodiment of the present invention. The term “communication network” is used herein to refer to any type of communication network, including customer-to-customer communication networks, internal customer communication networks, internal service provider communication networks, internal access provider communication networks, customer-to-service provider communication networks, customer-to-access provider communication networks, and access provider-to-service provider communication networks, as well as variations of the listed communication networks recognizable in the art. 
   Attention is now directed to  FIG. 2 , which includes a near-end environment and a far-end environment. The terms “near-end” and “far-end” are used herein to distinguish between two opposite-ended environments of the network  200  that share similar network components. For example only, the near-end environment is comprised of network components that include a customer premises equipment (CPE)  210 , a channel service unit (CSU)  220 , a network interface unit (NIU)  230 , an access provider (AP) network  240 , a point of interface (POI)  250  and a network element (NE)  260 . The far-end environment is comprised of network components that include a customer premises equipment (CPE)  215 , a channel service unit (CSU)  225 , a network interface unit (NIU)  235 , an access provider (AP) network  245 , a point of interface (POI)  255  and a network element (NE)  265 . The network components listed above are linked directly or indirectly using bi-directional communication technology that allows data exchange to and from each component. 
   As shown in  FIG. 2 , the network  200  comprises sub-environments including a near-end customer installation (CI), and near-end access provider (AP), a service provider (SP), a far-end access provider (AP), and a far-end customer installation (CI). Each of these sub-environments are shown to include one or more of the network components listed above. Additionally, the service provider sub-environment includes a service provider network  270 . In an exemplary embodiment, the service provider sub-environment includes a device outage detection system  299  which comprises a ticketing system  280 , a rules engine  282 , a test platform  284 , a customer notification system  286  and a work center  288 . One of ordinary skill in the art will recognize alternative embodiments that include the chronic error detection system  299  in environments other that the service provider sub-environment. 
   The access provider sub-environments provide a connection between the customer installation sub-environments and the service provider sub-environment. The service provider sub-environment provides a service to one or more customer installation environments. In one embodiment, the service is a telecommunications service, an Internet service, or a combination thereof. One of ordinary skill in the art will appreciate alternative services that are within both the scope and the spirit of the present invention. One of ordinary skill in the art will also appreciate alternative embodiments where the customer installation sub-environments and the service provider sub-environment connect directly to each other. 
   It should be recognized that the bi-direction communication technology of the network  200  is not limited to any particular type of communication technology. For convenience, however, embodiments of the present invention are generally described herein with relation to T1- and T3-based networks. One of ordinary skill in the art can easily adapt these implementations to other types of communication networks or communication systems. 
   While referring to  FIG. 3 , simultaneous reference will be made to  FIG. 2 .  FIG. 3  depicts a process flow diagram  300  representative of operation of the exemplary embodiment of the present invention. 
   According to  FIG. 3 , if a network device (e.g. the CPE  210 ) experiences an error (Block  310 ), the device outage detection system  299  will detect the existence of the error (Block  320 ). 
   In one embodiment, the device outage detection system  299  detects the existence of an error when it is reported by one or more components in the system  200 . For example, a customer associated with the customer premises equipment  210  may contact the device outage detection system  299  to report a service problem. Contact may be accomplished by any number of methods including, but not by way of limitation, calling the service provider, emailing the service provider, sending an embedded message to the service provider, or any other methods within both the scope and spirit of the present invention. 
   In another embodiment, the device outage detection system  299  detects when one or more errors occur in the system  200  by detecting signal abnormalities. The signal abnormalities may include service-affecting conditions that render all or a portion of a communication service inoperable, and performance-based conditions that inhibit the performance of a communication network. These conditions are generally measured by the standards of the American National Standards Institute. Alternatively, a service provider may set signal abnormality thresholds and determine that a power outage has occurred with reference to those thresholds. 
   Service-affecting conditions are common when a network component or a network circuit fails, powers down, or is out of service for other reasons. For example, the service-affecting conditions may include an alarm indication signal failure, a loss of frame failure, a loss of signal failure, a remote alarm indication failure and/or other alarm failures known in the art. 
   Performance-based conditions are common when there is poor signal quality or a loss of signal, and when a network component is dropping data (e.g. intermittent data packets). For example, the performance-based conditions may be indicated by performance management data such as performance report messages, network performance report messages, far end block error data, errored second data, severely errored seconds data, control source slips data, unavailable seconds data, bursty errored seconds data and/or other performance management data known in the art. In one embodiment, the performance monitoring data is measured against one or more predetermined threshold values to determine when an error exists in the system  200 . If the performance monitoring data exceed the one or more predetermined threshold values, then a performance-based condition exists. 
   In an exemplary embodiment, if the device outage detection system  299  detects an abnormality in the signal (e.g. alarm  212 ), the ticketing system  280  will receive an indication of the existence of the alarm  212  and forward a message to the rules engine  282  indicating that the alarm  212  was detected. The rules engine  282  then begins an automated test to determine whether the alarm  212  is a result of a power outage. 
   To start, the rules engine  282  instructs the test platform  284  to contact the (e.g. the CPE  210 ) that originated the alarm  212  (Block  330 ). In an exemplary embodiment, the test platform  284  tries to contact the network device by dialing out of band. Dialing out of band (OOB) is a connectivity method that transmits signals without using any part of the transmission channel capacity reserved for subscriber traffic. Although the term “out of band” is normally used to describe transmissions utilizing a different frequency band than the speech signal, as is the case for older frequency division multiplexing device where different bands of frequencies are involved, it is also defined herein to include modern digital transmissions that use different digital bits than those reserved for the subscriber traffic. 
   If the test platform  184  connects with the CPE  210 , then the rules engine  282  determines that the alarm  212  is not due to a power outage at the CPE  210 . If the test platform  284  cannot connect with the CPE  210 , then the test platform  284  tries to connect with the CSU  220  (Block  340 ). In an exemplary embodiment, the test platform  284  tries make a connection by looping the CSU  220 . Data returned from the looping attempt will indicate whether the test platform  284  could connect with the CSU  220 . 
   If a connection could not be made between the test platform  284  and the CPE  210 , and if an attempt to establish contact between the test platform  284  and the CSU  220  associated with the alarm  212  fails, then the rules engine  282  determines that the alarm  212  is due to a power outage (Block  350 ). 
   An alternative step may be inserted if the test platform&#39;s  284  attempt to connect with the CSU  220  is unsuccessful. This steps provides that an attempt to loop the NIU  230  is performed by the test platform  284 . In this alternative embodiment, if looping of the NIU  230  is successful, then the rules engine  282  determines that the error at the CPE  210  is due to a power outage (Block  550 ). If looping of the NIU  230  is unsuccessful, then the rules engine  282  performs additional diagnosis to identify the type error that triggered the alarm  212 . 
   If the rules engine  282  determines that the alarm  212  is due to a power outage, the ticketing system  280  begins repair coordination. In one embodiment, the repair coordination consists of contacting the customer via the customer notification system  286  to confirm that the alarm  212  resulted from a power outage (Block  360 ). In another embodiment, the repair coordination consists of assigning the repair of the power outage to the work station  288  (Block  370 ). The work station  288  may comprise one or more technicians or may be fully automated. After receiving the assignment from the ticketing system  280 , the work station  288  schedules maintenance of the CPE  210 , resets/repairs the CPE  210 , instructs the customer how to reset/repair the CPE  210 , and/or assigns the repair to another work station. 
   In an exemplary embodiment, when the CPE  210  returns from its power outage to a powered up state, the rules engine  282  will determine whether the CPE  210  supports a “reason for last reboot” query. A “reason for last reboot” is an indication sent from the CPE  210  that provides information regarding the reason for the CPE&#39;s  210  last reboot. If the CPE  210  supports such a query, then the test platform  284  queries the CPE  210  to confirm the reason for the CPE  210 &#39;s last reboot (Block  380 ). If it&#39;s last reboot is due to a power outage, the diagnosis for the cause of the alarm  212  completes. 
   Thus the rules engine and error isolation algorithm provide a method for efficiently determining whether a power outage has occurred that is disrupting customer service. The arrangement, relying on one or more programmed processors, and the rules based engines decreases the need to rely on technicians do process analyze, and respond to alarms. 
   In conclusion, the present invention provides, among other things, a system and methods for detecting and isolating errors in a communication network. Those skilled in the art can readily recognize that numerous variations and substitutions may be made in the invention, its use and its configuration to achieve substantially the same results as achieved by the embodiments described herein. Accordingly, there is no intention to limit the invention to the disclosed exemplary forms. Many variations, modifications and alternative constructions fall within the scope and spirit of the disclosed invention as expressed in the claims.