# Simultaneous Transmission of Photonic Services over One Fiber with an ITU 100 GHz Grid
## 4 Results and Discussion  
During the measurement, different fibers were emphasized. Initial testing was conducted using a photonic service (accurate time), sensory system, and data transfer. Each of the services was defined by its own wavelength. Measurement of the bit error rate was performed automatically using Coriant Groove\({}^{TM}\) G30 in a \(1\,\mathrm{min}\) period. The authors aimed at demonstrating the possibilities of data flow being influenced by the pulse sensory system. It can be assumed that low power duration will result in the availability of a service throughout the testing, whereas a gradual increase in pulse duration will eventually affect the data signal. The data signal was not the only service being monitored. The accurate time transmission allows for evaluating the delay per fiber. Optical fibers are defined by their type and refractive index. After each of the optical fibers was measured, a combination of G.652D and G.653 fibers was created. The measured values of pre-forward error correction-bit error rate (pre-FEC-BER) indicate the error rate prior to applying any correction algorithm. Figure 4 shows the results for G.652D and G.653 fibers. As seen, the associated pre-FEC-BER values are independent and show a certain scattering pattern. However, linear dependence cannot be assumed at this point. The scattering could theoretically be eliminated by using a longer measuring section. For our measurement, the section of one minute was chosen. Coriant GrooveTM G30 supports measuring ranges of 1, 15, or 60 min. As more emphasis is put on proving an influence among the services, the use of longer sections was not necessary. The pre-FEC-BER values are indicative of the measurements. However, as seen in Figure 4, the values of pre-FEC-BER gradually decrease as the increasing power of the sensor system affects the data transmission. It should be pointed out that for the G.652D fiber, i.e., the standard telecommunication fiber, the accurate time transmission was stable for all tested pulse durations and output power values of the erbium-doped fiber amplifier (EDFA). The average time delay was \(\approx\)35,328.415 ns. On the right side of Figure 4, measurements of a single G.653 fiber are visualized. With the increasing sensor system's power, the values of the pre-FEC-BER deteriorated by an order of magnitude in comparison to those of G.652D. The accurate time transmission dropped out immediately after increasing the sensing system's power from 25 dBm to 26 dBm even for the shortest pulse, with a pulse duration of 20 ns. After extending the pulse duration from 20 to 500 ns, the accurate time transmission showed errors from the sensory system's power of 23 dBm. Another increase in pulse duration up to 800 ns did not affect the accurate time transmission, as the transmission failure occurred again after the sensory system's power increased from 22 to 23 dBm. Next, the pulse duration was raised again to 1 us, where the accurate time transmission showed frequent errors (no delay value displayed) from the power of 22 dBm. This trend is reflected by decreasing the pre-BER-FEC values on Coriant GrooveTM G30, as seen in Figure 4 (on the right side). As a result, G.653 fiber was found to be the least appropriate to conduct simultaneous transmission of photonic services. The average accurate transmission time delay was \(\approx\)34,968,292 ns. The previous two fibers had the same length of 7 km. In comparison, G.655 fiber has a length of 10 km. The results for the G.655 fiber measurement are very similar to those of G.652D. Figure 5 (on the left side) shows the measured pre-FEC-BER values for the G.655 fiber. In comparison with the previous examples, the largest scattering is found by using this particular fiber. As mentioned above, these errors are caused by the measurement methodology when a very short section was chosen to measure the data sequence during the evaluation.