channels to support a combined bit rate in the range of . Parameters Bandwidth–distance product Because the effect of dispersion increases with the length of the fiber, a fiber transmission system is often characterized by its bandwidth–distance product, usually expressed in units of MHz·km. This value is a product of bandwidth and distance because there is a trade-off between the bandwidth of the signal and the distance over which it can be carried. For example, a common multi-mode fiber with bandwidth–distance product of 500 MHz·km could carry a 500 MHz signal for 1 km or a 1000 MHz signal for 0.5 km. Record speeds Using wavelength-division multiplexing, each fiber can carry many independent channels, each using a different wavelength of light. The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the forward error correction (FEC) overhead, multiplied by the number of channels (usually up to eighty in commercial dense WDM systems ). Standard fiber cables The following summarizes the current state-of-the-art research using standard telecoms-grade single-mode, single-solid-core fiber cables. The 2016 Nokia/DT/TUM result is notable as it is the first result that pushes close to the Shannon theoretical limit. The 2011 KIT and 2020 RMIT/Monash/Swinburne results are notable for having used a single source to drive all channels. Specialized cables The following summarizes the current state-of-the-art research using specialized cables that allow spatial multiplexing to occur, use specialized tri-mode fiber cables or similar specialized fiber optic cables. The 2018 NICT result is notable for breaking the record for throughput using a single core cable, that is, not using spatial multiplexing. The 2022 TUD result is notable for breaking the record for throughput using a photonic chip. New techniques Research from DTU, Fujikura & NTT is notable in that the team was able to reduce the power consumption of the optics to around 5% compared with more mainstream techniques, which could lead to a new generation of very power-efficient optic components. Research conducted by the RMIT University, Melbourne, Australia, have developed a nanophotonic device that has achieved a 100 fold increase in current attainable fiber optic speeds by using a twisted-light technique. This technique carries data on light waves that have been twisted into a spiral form, to increase the optic cable capacity further, this technique is known as orbital angular momentum (OAM). The nanophotonic device uses ultra thin topological nanosheets to