January 01, 2018

QoS-aware protection in flexgrid optical networks

Elastic optical networks generally rely on protection and restoration mechanisms to prevent the detrimental effect of fiber cuts. In particular, we investigate optical protection in flexgrid optical networks where the symbol rate is varied as a complementary approach to modulation format. We propose a novel protection scenario, whereby premium traffic survives cuts with just-enough bandwidth, which we call ""quality-of-service-aware protection"" (QoS-aware protection). The proposed mechanism exploits a variable baud rate transponder in order to reduce the spectrum occupancy of the protecting path and to ease the establishment of new traffic demands. Equipped with two lasers and optical switches, the QoS-aware node allows fast switching between different working and protecting bit rates. The two wavelengths also help to reduce the spectrum fragmentation. We compute typical spectral usage boosted by 80% to protect 25% of premium traffic with respect to current 1 + 1 protection. We demonstrate a field programmable gate array (FPGA)-based proof-of-concept node of QoS-aware protection that reconfigures in <2.8 ms. We program and select the ratio of premium versus best effort traffic as a tunable input parameter of the proof-of-concept.

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Recent Publications

January 01, 2018

Fair Dynamic Spectrum Management for QRD-Based Precoding with User Encoding Ordering in Downstream G.fast Transmission

In next generation DSL networks such as G.fast, employing discrete multi-tone transmission in high frequencies up to 212 MHz, the crosstalk among lines reaches very high levels. To precompensate the crosstalk in downstream transmission, QRD-based precoding has been proposed as a near-optimal dynamic spectrum management (DSM) technique. However, the performance ...

January 01, 2018

Practical Mitigation of Passive Intermodulation in Microstrip Circuits

This paper presents new experimental evidence and a novel practical approach for mitigation of passive intermodulation (PIM) in microstrip circuits fabricated on commercial printed circuit board laminates. The mechanisms of distributed PIM in microstrip circuits are reviewed and a phenomenology of PIM generation due to locally enhanced electromagnetic fields at ...

January 01, 2018

Efficient Cooperative HARQ for Multi-Source Multi-Relay Wireless Networks

In this paper, we compare the performance of three different cooperative Hybrid Automatic Repeat reQuest (HARQ) protocols for slow-fading half-duplex orthogonal multiple access multiple relay channel. Channel State Information (CSI) is available at the receiving side of each link only. Time Division Multiplexing is assumed, where each orthogonal transmission occurs ...