Abstracts:Recently, a novel passive optical network (PON) has been proposed based on orthogonal frequency division multiple access (OFDMA) technology. The OFDMAPON provides the opportunity for the convergence of wireline and wireless services. Moreover, virtual subcarrier scheduling can be achieved by virtualization, thus hiding the difference of heterogeneous multiplexing methods in the OFDMA-PON supporting wireline and wireless services. In the multi-segment OFDMA-PON topology, each segment is connected to a distribution fiber. If all distribution fibers are under maintenance simultaneously, the service continuity will be disrupted, thus necessitating an appropriate virtual subcarrier scheduling scheme. In this paper, by migrating the traffic of virtual subcarriers during each maintenance batch, only a partial set of distribution fibers is maintained, leaving the remaining ones to fully support the operation. We formulate the problem aiming to minimize the number of maintenance batches while guaranteeing an acceptable scheduling period. The NPhard problem, feasibility conditions, and lower bound are analyzed. We also design a novel virtual subcarrier scheduling algorithm to solve the problem. Simulations show that the heuristic solution well matches the lower bound with a high convergence ratio of 93%. The optimal scheduling period is also determined.

Abstracts:Future many-core processors will require high-performance yet energy-efficient on-chip networks to provide a communication substrate for the continually increasing number of cores on one chip. Optical networkon- chip (ONoC) is employed as a promising candidate interconnection solution for its high bandwidth and low energy consumption. However, optical circuit-switching (OCS) based architectures face the problem of high network congestion, low network utilization, and an overhead in power dissipation under heavy loads. In this paper, we propose an ONoC architecture with time-division multiplexing (TDM) and wavelength-division multiplexing (WDM) technology to solve the network contention problem faced by OCSbased ONoC. The number of wavelength groups and timeslots is optimized by using a genetic algorithm. A new optical router is designed to realize our TDM–WDM communication technology. A detailed model is built to analyze insertion loss and crosstalk noise. The simulation results show that TDM–WDM-based ONoC has better performance compared with equivalent OCS-mesh ONoC under a uniform traffic pattern. Similar analysis can be drawn for the real science application based on the PARSEC benchmark.

Abstracts:Due to the growing popularity of optical superchannels and software-defined networking, reconfigurable optical add-drop multiplexer (ROADM) architectures for superchannel switching have recently attracted significant attention. ROADMs based on micro-electro-mechanical system (MEMS) and liquid crystal-on-silicon (LCoS) technologies are predominantly used. Motivated by requirements for low power, high-speed, small area footprint, and compact switching solutions, we propose and demonstrate spatial and wavelength flexible superchannel switching using monolithically integrated silicon photonics (SiP) micro-ring resonators (MRRs). We demonstrate the MRRs’ capabilities and potential to be used as a fundamental building block in ROADMs. Unicast and multicast switching operation of an entire superchannel is demonstrated after transmission over 50 km of standard single mode fiber. The performance of each sub-channel from the 120 Gb∕s QPSK Nyquist superchannel is analyzed, and degradation in error vector magnitude performance was observed for outer sub-channels due to the 3 dB bandwidth of the MRRs, which is comparable with the superchannel bandwidth. However, all sub-channels for all switching cases (unicast, multicast, and bi-directional operation) exhibit performance far below the 7%FEClimit. The switching time of the SiPMRRchip is such that high-capacity superchannel interconnects between users can be set up and reconfigured on the microsecond time scale.