| mdi/SingTel Optus service roll-out case study |
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The large Australian carrier, Optus part of the SingTel Group, was experiencing high bit error rates (BER’s) on a recently installed ROADM based Long Haul DWDM system. The carrier was concerned about 2 routes between the same points, one Inland and one Coastal. Each approximately 1200km (750 miles) long. The Inland route was suffering from relatively high pre-FEC (forward error correction) BER’s on some of it’s 10Gbit/s channels. Aware of the capabilities of mdi’s eyeD 360 network appliance, the carrier called in the eyeD Expert team to carry out tests and identify the reasons for the high BER’s, confirm levels of OSNR, CD, and PMD to ensure this new system was running optimally and pinpoint ways of improving it further, without taking down live services. Optus knew that the inland route contained some sections of legacy fiber with PMD, and also suspected that low OSNR’s were a factor. The carrier had implemented their own polarization-nulling technique on a standard optical spectrum analyzer (OSA) to try to get more accurate figures for “true OSNR” when commercial instruments utilizing this technique had proved unsuccessful in trials. Also, as the system was now live, they could not remove traffic to analyze the fibers for PMD. While the system vendor had optimised dispersion to minimize BER levels, no independent CD measurement had been made to confirm the level of residual CD. The eyeD Expert team was able to rapidly calibrate for the new transponder type, and give the carrier reassurance both on residual CD and PMD levels on the problem route as well as provide independent expert advice. Optus was very impressed with the eyeD 360’s ability to measure true OSNR where other commercial instruments had failed and the level of expertise and speed with which the eyeD Expert team carried out the engagement. Download Optus case study |