What is fractional QAM?
Tackling soaring data demand
Today’s cloud and internet content providers urgently need to achieve more with their existing regional, long-haul and submarine infrastructure. Communication service providers too are looking to increase the capacity of their deployed transport networks in order to handle data rates that are increasing at around 30% every year. Against this background of spiraling demand, fractional QAM has emerged as an invaluable lifeline.
Coherent bandwidth optimized
With fractional QAM enabling ultra-flexible modulation, a fixed grid structure is no longer a barrier to growth.

As shown in major trials with commercial networks, ultra-flexible modulation using fractional QAM has achieved unprecedented levels of spectrum efficiency.
Balancing capacity and distance
Operators now have a way to significantly reduce cost-per-Gigabit-mile in brownfield and subsea scenarios.

Stepping up
Fractional QAM modulation offers a way to boost network capacity even over legacy networks, ensuring the lowest opex for any link. Other coherent transponders make use of a limited range of bit-per-symbol and symbol rate options. But these discrete steps often fail to achieve the ideal balance between capacity and reach. Fractional QAM modulation technology leverages the many small increments in between, enabling more options to suit a far wider range of fiber conditions. This means that, for any traffic demand over any distance, data is transmitted with the lowest spectral occupation. Likewise, for a fixed spectral slot (say 50GHz or 100GHz) on any given lightpath, fractional QAM maximizes the transmitted capacity.
Ultra-flexible transport
With new terminal technology, enabling massive capacity increase is simple and cost-effective.

A new level of efficiency
As shown in major trials with commercial metro, data center interconnect and long-haul networks, ultra-flexible modulation using fractional QAM has achieved unprecedented levels of network efficiency. Trials involving our commercially available FSP 3000 TeraFlex™ terminal have shattered industry records for capacity-distance product. We’ve proven that dramatic bandwidth increases are now possible without expensive optical line system upgrades, opening the door to the full business potential of 5G and IoT applications.
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