March 01, 2017

Field Trial of a 1 Tbit/s Super-Channel Network Using Probabilistically Shaped Constellations

  • Buchali F.
  • Idler W.
  • Lach E.
  • Schmalen L.

We successfully tested the suitability of probabilistically shaped constellations in a German nationwide fibre ring of the R&D field test network of Deutsche Telekom. In this ring eight German cities can be reached by add/drop nodes implemented by passive optical add/drop multiplexers, offering 12 bands of 400 GHz widths at the extended C-band. Multiple cascaded add/drop multiplexer are reducing the available bandwidth and we respectively applied of 150 GHz and 200 GHz, to transmit a 1 Tbit/s 4-carriers super-channel with an extended family of probabilistically shaped constellations using 16QAM, 36QAM and 64QAM. We verified in the field environment by two examples, that probabilistically shaping is outperforming standard 64QAM formats in reach. We experimentally tested two typical 1 Tb/s working paths with 420km and 920km demonstrating spectral efficiencies of 6.75 and 5 bit/s/Hz. The reach of about 1500km was extrapolated for a 1 Tb/s super-channel in a 200 GHz bandwidth. For longer distances the bitrates have to be reduced and for the longest bi-directional path of the test network, i.e. a protection path of 2,160 km, the maximum bitrate was 800 Gb/s

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Recent Publications

June 19, 2017


  • Cammerer S.
  • Hoydis J.
  • Leible B.
  • Stahl M.
  • Ten Brink S.

The decoding performance of polar codes strongly depends on the decoding algorithm used, while also the decoder throughput and its latency mainly depend on the decoding algorithm. In this work, we implement the powerful successive cancellation list (SCL) decoder on a GPU and identify the bottlenecks of this algorithm with ...

June 04, 2017

A New PRACH Transmission Scheme in Unlicensed Spectrum

  • Luo Z.
  • Meng Y.
  • Tao T.

For the unlicensed spectrum, the occupied bandwidth requirement is demanded by some regulations. The legacy scheme of Physical Random Access Channel (PRACH) for Long Term Evolution (LTE) cannot satisfy it. In this paper, we propose a novel PRACH transmission scheme to satisfy the requirement of unlicensed spectrum based on preamble ...

June 01, 2017

Mutual service processes in Euclidean spaces: existence and ergodicity

  • Baccelli F.
  • Mathieu F.
  • Norros I.

Consider a set of objects, abstracted to points of a spatially stationary point process in R-d, that deliver to each other a service at a rate depending on their distance. Assume that the points arrive as a Poisson process and leave when their service requirements have been fulfilled. We show ...