Overview on Optical Fronthauling Technologies for Fixed-Mobile Convergence

We present in this Chapter an overviewof optical fronthauling technologies for fixed-mobile convergence in next generation 5G access networks. The Chapter first introduces the general concept of Cloud Radio Access Network, or C-RAN, then it presents the most common proposals for fronthauling, based on Digitized Radioover- Fiber, or D-RoF, according to the CPRI or OBSAI standards. The Chapter then prosecutes by presenting the very recent evolutions of D-RoF toward the "functional split" paradigm, as already available in the latest releases of the CPRI specifications. Finally, some recent research trends towards Analog RoF are presented. The Chapter is intentionally written in a tutorial way, to be used by newcomers in this field. It anyway also reports a vast set of bibliographic references to guide the interested reader toward more detailed technical presentations

Electronic equalization for advanced modulation formats in dispersion-limited systems

We investigate in this letter the use of electronic equalization on dispersion limited systems for different modulation formats. Besides analyzing equalization on standard NRZ intensity modulation as a reference, we focus on two advanced modulation formats, Duobinary and Differential Phase Shift Keying (DPSK) which are recently gaining large attention. We demonstrate that the introduction of an electronic equalizer strongly improves standard NRZ performance, whereas it has a limited effect on Duobinary and DPSK formats. Moreover, we give rules for the optimal choice of the equalizer transversal filter parameters, i.e., the number of taps and the delay between taps

Review and comparative assessment of FDMA-PON vs. TDMA-PON for next-generation optical access networks

We present in this paper a comparative assessment of Time Division Multiple Access Passive Optical Networks (TDMA-PON) and Frequency-Division Multiple Access Passive Optical Networks (FDMA-PON). We try to point out the pros and cons of the two different approaches in the context of very high capacity next-generation PON mainly in terms of physical layer transmission performances, but also introducing some comparison in terms of complexity, cost and power consumption

Next generation passive optical networks using frequency division multiplexing

We discuss the use of frequency division multiplexing in next-generation PON. We start by discussing pros and cons of FDMA compared to traditional TDMA approach, then present the latest results from the EU project FABULOUS

Synchronization of a WDM Packet-Switched Slotted Ring

In this paper, we present two different strategies of slot synchronization in wavelength-division-multiplexing (WDM) packet-switched slotted-ring networks. Emphasis is given to the architecture behind the WDM Optical Network Demonstrator over Rings (WONDER) project, which is based on tunable transmitters and fixed receivers. The WONDER experimental prototype is currently being developed at the laboratories of Politecnico di Torino. In the former strategy, a slotsynchronization signal is transmitted by the master station on a dedicated control wavelength; in the latter, slave nodes achieve slot synchronization aligning on data packets that are received from the master. The performance of both synchronization strategies, particularly in terms of packet-collision probability, was evaluated by simulation. The technique based on transmitting a timing signal on a dedicated control wavelength achieves better performance, although it is more expensive due to the need for an additional wavelength. However, the technique based on aligning data packets that are received from the master, despite attaining lower timing stability, still deserves further study, particularly if limiting the number of wavelengths and receivers is a major requirement. Some experimental results, which were measured on the WONDER prototype, are also shown. Measurement results, together with theoretical findings, demonstrate the good synchronization performance of the prototype