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• An optical band-pass filter-assisted offset DSB direct-detection receiver is proposed for low-cost data center interconnect applications. • The proposed scheme uses an OBPF to filter out the optical carrier as the local oscillator for the receiver. As such, signal-signal beat interference can be eliminated. • Compared with the previous offset DSB CADD scheme, the optimal CSPR of the proposed scheme can be reduced to less than 0 dB, and the OSNR sensitivity can be significantly improved. • The effectiveness of the proposed offset DSB self-coherent detection is fully verified by simulation. The numerical results show the potential of proposed scheme. The offset double-sideband (DSB) scheme has attracted attention because it can achieve field recovery at low carrier-to-signal power ratio (CSPR) and improve the spectral efficiency (SE) of self-coherent detection. In this paper, an offset DSB filter-assisted direct detection (FADD) scheme is proposed and studied for the first time, which uses an optical bandpass filter (OBPF) to filter out the optical carrier as the local oscillator for the receiver. As such, signal-signal beat interference (SSBI) can be eliminated. Since the offset DSB signal has a large frequency gap, the requirement for the bandwidth of the OBPF is not high. The performance of the proposed offset DSB FADD scheme is evaluated for 16-QAM signals. It is comprehensively compared with offset DSB carrier-assisted differential detection (CADD) scheme in terms of OSNR sensitivity, optimal CSPR, and receiver power sensitivity. In addition, the effect of frequency gap compression is significant as SSBI is completely eliminated from the system, thereby utilizing as many low-frequency resources as possible and improving SE. Finally, the proposed offset DSB FADD scheme is resilient to the wavelength offset up to several GHz between the transmitter laser and the center wavelength of the OBPF. [ABSTRACT FROM AUTHOR]

Increased demands for web and cloud-based services have been driving exponential growth of datacenter bandwidth. This paper discusses, from Google’s perspective, emerging challenges and possible technical solutions for scaling intra-datacenter and intra-campus interconnection network bandwidth. [ABSTRACT FROM AUTHOR]

On the basis of profound understanding of data center (DC) traffic demands and optical switching technologies, we present a hybrid optical network design for future data center network (DCN). Such design integrates optical circuit switching (OCS) and optical packet switching (OPS) schemes via hybrid Top-of-the-Rack (ToR) switches which provide flexible function-switchover between different traffic patterns in the DCN. Simulations of network behaviors under such DC traffic loads indicate that the proposed OPS/OCS DCN can effectively improve the network performance. Moreover, via a preliminary analysis of OCS and OPS network configurations, the construction of hybrid DCN is also proved as the most cost- and energy-efficient way for DCN upgrading while offering a promised quality of service. An experimental demonstration shows a complete implementation of data center virtualization in the proposed hybrid data center network. [ABSTRACT FROM AUTHOR]

Universal fiber is a multimode fiber that has an LP 01 mode field diameter approximately matched to that of standard single-mode fiber. It can transmit both multimode and single-mode signals using transceivers designed for either multimode fiber or single-mode fiber. By using universal fibers, one can bridge the needs for both single-mode and multimode transmission through a uniform and simplified cable infrastructure to accommodate the full distance range needed, while having upgradability from 10G to 40G to 100G and to even higher data rates. We build on our previous work that analyzed the dependence of LP 01 mode-field diameter on fiber parameters, and the coupling loss for both single-mode and multi-mode transmission, with a further study of mode coupling and multiple path interference associated with single-mode operation. We demonstrate system performance in both single-mode and VCSEL-based multimode transmissions for a number of 100G transceiver types using a QSFP form factor − the preferred choice in data centers. [ABSTRACT FROM AUTHOR]

With the rapid growth of data center services, the elastic optical network is a very promising networking architecture to interconnect data centers because it can elastically allocate spectrum tailored for various bandwidth requirements. In case of a link failure, to ensure a high-level quality of service (QoS) for user request after the failure becomes a research focus. In light of it, in this paper, we propose and experimentally demonstrate multipath protection for data center services in OpenFlow-based software defined elastic optical network testbed aiming at improving network reliability. We first propose an OpenFlow-based software defined elastic optical network architecture for data center service protection. Then, based on the proposed architecture, multipath protection scheme is figured based on the importance level of the service. To implement the proposed scheme in the architecture, OpenFlow protocol is extended to support multipath protection in elastic optical network. The performance of our proposed multipath protection scheme is evaluated by means of experiment on our OpenFlow-based testbed. The feasibility of our proposed scheme is also demonstrated in software defined elastic optical networks. [ABSTRACT FROM AUTHOR]

Due to the performance guarantee of low delay, huge bandwidth and high reliability at a low cost, IP over Flexi-Grid optical network is a very promising networking architecture applied to the interconnection of geographically distributed data centers. It can enable efficient resource utilization and support heterogeneous bandwidth demands in cost-effective, highly-available and energy-effective manner. In case of edge Flexi-Grid optical network node failure, to ensure a high-level quality of service (QoS) for user request after the failure becomes a research focus. In this paper, we propose a novel service-aware resources integrated resilience (SA-RIR) scheme for data center services in software defined data center networking architecture based on IP over Flexi-Grid optical networks. Different from previous works which restore the services just exploiting the optical stratum, the proposed scheme provides the resilience using the multiple stratums resources in case of the edge optical node failure. We quantitatively evaluate the feasibility and performances through the simulation under heavy traffic load scenario in terms of path blocking probability, path resilience latency and resource occupation rate with different failure rates. Simulation results show that, the SA-RIR scheme can enable joint optimization of IP network, Flexi-Grid optical network and data center application stratum resources, and enhance the data center service resilience responsiveness to the dynamic end-to-end demands. [ABSTRACT FROM AUTHOR]