ISE Magazine, May 2019

I S E I C T S O L U T I O N S E D U C AT I O N 8 Fault locating the copper infrastructure for bandwidth with the advent of IoT The ongoing expectation of extended reliable and quality bandwidth has always been a maintenance challenge for field technicians and that challenge has increased exponentially with the addition of IoT services While fiber to thehome is the ideal solution for delivering bandwidth for now many residential customers depend on copper as the final step in supplying high end services including IoT Field technicians get dispatched on a myriad of problems to restore service especially on bandwidth circuits that are fiber to the node FTTN They are responsible for the cable pair the drop inside station wire if applicable Wi Fi modems and other end user equipment In the old days a POTS customer could describe problems to the technician Today with machines talking to machines troubleshooting can be tougher With increasing IoT and other high end applications keeping a bandwidth customer happy requires a proactive effort from all involved Quality testing before dispatch can save truck rolls but once the technician is dispatched the ball is in his court The first step is the most important and the most difficult Knowing where to start The best approach for the technician is to make sure that the narrow band POTS portion riding on the cable pair is functioning properly The cable pair must be free of DC type faults Any short ground cross crossed battery should be repaired and the cable pair should be tested for series resistance and unacceptable capacitive balance Then testing at the network interface for acceptable loop current network interface ground circuit loss circuit noise power influence and longitudinal balance is a must before proceeding to the wideband side of the house Surprisingly many technicians may not be fully aware of the parameters for quality POTS service In the process of restoring service the time sensitive field technician often overlooks these parameters so lets take a look Most bandwidth circuits do not require loop current When needed loop current must provide sufficient current flow to operate supervision and signaling equipment such as dial tone request or the touch pad on a POTS circuit Some circuits such as a signaling circuit provide their own current Insufficient loop current might be the COPPER EXPERT dmccarty@ mccartyinc com For more information email or visit www mccartyinc com Don McCarty is the Copper Expert columnist for ISE magazine discussing the issues around provisioning testing and maintaining copper for all services from POTs to IPTV Don is also President of and the Lead Trainer for McCarty Products a technical training and products company training field technicians cable maintenance installation repair and Central Office technicians and managers