Meeting the future metro network challenges and requirements by adopting programmable S-BVT with direct-detection and PDM functionality

Abstract

In this paper, we propose an advanced programmable sliceable-bandwidth variable transceiver (S-BVT) with polarization division multiplexing (PDM) capability as a key enabler to fulfill the requirements for future 5G networks. Thanks to its cost-effective optoelectronic front-end based on orthogonal frequency division multiplexing (OFDM) technology and direct-detection (DD), the proposed S-BVT becomes suitable for next generation highly flexible and scalable metro networks. Polarization beam splitters (PBSs) and controllers (PCs), available on-demand, are included at the transceivers and at the network nodes, further enhancing the system flexibility and promoting an efficient use of the spectrum.

Programmable SDN-Enabled S-BVT Based on Hybrid Electro-Optical MCM

“…Alternative schemes, such as OFDM can also be considered by including at the transmitter/receiver DSP an upconversion/downconversion block in order to generate a real-valued signal. The same spectral efficiency than DMT can be achieved by selecting a radio frequency of half the signal bandwidth [20]. The multicarrier DSP block includes data parallelization and mapping, training symbol insertion, inverse fast Fourier transform (IFFT) implementation, cyclic prefix (CP) insertion and serialization.…”

“…The multicarrier DSP block includes data parallelization and mapping, training symbol insertion, inverse fast Fourier transform (IFFT) implementation, cyclic prefix (CP) insertion and serialization. Additionally, the Levin Campello (LC) BL/PL algorithm is applied in order to flexibly allocate different power values and modulation formats to the different subcarriers according to the channel profile, which is obtained by estimating the signal-tonoise ratio (SNR) of each subcarier [9], [20]. Hence, the impact of transmission impairments (e.g.…”

“…CD) and hardware limitations (e.g. DAC bandwidth) on the system performance can be reduced [20]. Different loading algorithms can be applied including LC-rate adaptive (RA) or LC-margin adaptive (MA) [9].…”

“…At the DSP level, a randomly generated data stream is parallelized and mapped into different modulation formats, including BPSK and optimized m-QAM constellations (m = 2 l ; 2 ≤ l ≤ 8), according to the BL/PL algorithm for adaptive mapping [20]. The SNR per subcarrier is estimated to activate the BL/PL algorithm (LC-RA) in order to adapt/reconfigure the transmitter to maximize system capacity [20]. An example of the resulting SNR estimation and bit assignment per subcarrier for the implementation of AM/CO, after 25 km of standard single mode fiber (SSMF), can be seen in the insets (b) and (c) of Fig.…”

Sliceable BVT Evolution Towards Programmable Multi-Tb/s Networking

“…training symbols, TS) allocated for channel estimation and equalization [11].In addition to spectrum, other dimensions can also be exploited, such as polarization and space, in order to further increase system/network capacity. Polarization division multiplexing (PDM) allows doubling of spectral efficiency (SE), as well as introduces an additional dimension that can be used for routing additional traffic in dense fiber links [12]. Space division multiplexing (SDM) allows scaling of the capacity of a factor, depending on the number of fibers/cores and/or modes used in case of the adoption of fiber bundles or multicore fibers (MCF) and/or multimode (few-mode) fibers [13].…”