System Architecture & Details

Figure below shows the overall system Architecture.

    The overall system comprises a number of system elements. Some of these elements, namely, NMS systems, Optical Outside plant and Wireless Communication network already exist, however, there are a few that are slated to be designed and developed during the course of this project.

    The systems shown in light green box (lower left corner of the figure) runs the SW functionality that is being designed and developed. It comprises integrated GIS and NMS engines which have been integrated using a new Interconnect SW module. A new Fiber Management SW Module that enhances the functionality of an existing GIS engine to help perform the Fiber Management functions. Another new SW module enhances the functionality of an existing NMS engine to be a Master Network Management System or “Manager of Mangers”. A separate GUI module provides a unified view for all of the above mentioned SW modules. This integrated SW infrastructure also interfaces with a number of other communication SW modules that not only facilitates remote communication with the optical test equipment in the field but also provides alerts to the designated staff.

    One key objective of the project is to enable the operational support personnel to perform swift fiber cut repairs in emergencies. While fiber cuts can only be repaired manually, the time it takes to determine the exact location of the fiber cut is quite critical to dispatch the team to the correct location to execute repairs. The location of a fiber cut is determined with the help of optical test equipment known as Optical Time Domain Reflectometer (OTDR). This equipment is quite expensive and is, therefore, strategically located at a few key locations in the network. In the event of the breakdown of a link in a section, the troubleshooting procedure is mainly manual and takes some time before other reasons for the loss of signal are ruled out and fiber cut is considered a reason for the loss of optical signal. Any degree of automation in this regard is quite helpful. A complete automation is the ideal scenario barring the cost of the solution. We have determined that there are two scenarios that this project should cater for to meet its objective to enable the operational support personnel to perform swift fiber cut repairs in emergencies.

    The first scenario is a semi automated scenario in which, on activation of the relevant alarms, existing equipment is used to perform a fiber cut measurement. The results are communicated to the experts in NOC using the existing mobile wireless networks. This requires development of an interface HW and SW that interfaces to the existing OTDRs to execute remote commands and send the resultant output test data to the remote site using the existing GSM network.  The main drawbacks in this scenario are that existing OTDR are too expensive and need to be manually placed at the desired termination point.

    The shortcomings of the 1^st scenario can be overcome by permanently installing a number of OTDR at strategic location through out the network. But this scenario is deemed too expensive for large scale deployment because of the costs involved in the current commercial OTDR. Thus, a low cost, no non-sense features, OTDR is desirable and can provide excellent value to the service operators. 

    The yellow box (upper right hand coroner) in above figure signifies these two components in the System architecture, the custom communication interface and the essential functionality Custom Optical Test Unit (essentially an OTDR) that are being developed as part of this project.