Data Center Interconnects at 400G and Beyond

Current trends in Data Center Interconnectivity are considered in the light of increasing traffic and under the constraint of limited cost and power consumption.Comment: This project has received funding from the European Union Horizon 2020 research and innovation programme under grant agreement No 762055 (BlueSpace project) and from the German ministry of education and research (BMBF) under contract 16KIS0477K (SENDATE Secure-DCI project

Re-telling, Re-cognition, Re-stitution: Sikh Heritagization in Canada

In Canada, the language and techniques of museums and heritage sites have been adopted and adapted by some immigrant communities to make sense of their place within their new country. For some groups, “heritagization” is a new value, mobilized for diverse purposes. New museums and heritage sites serve as a form of ethnic media, becoming community gathering points, taking on pedagogical roles, enacting citizenship, and enabling strategic assertion of identity in the public sphere. This article explores this enactment of heritage and citizen-membership through a case study, the Sikh Heritage Museum, developed in Abbotsford by Indo-Canadians. Established in 2011 in an historic and still-functioning gurdwara, the museum is an example of a community’s desire to balance inward-looking historical consciousness and community belonging, with outward-looking voice, recognition and acceptance by mainstream Canadian society. The museum has also become a site of tension between top-down and bottom-up initiatives, where amateur and local expressions butt up against professionalized government activities such as the Canadian Historical Recognition Program that seek to insert formal recognition and social inclusion policies. The article considers the effects of this resource and power differential on the museum’s development, and on the sensibilities and practices of immigrant “heritage” and “citizenship” in Canada

Accurate Measurement of Propagation Delay in a Multi-Span Optical Link

The principle of Correlation Optical Time Domain Reflectometry (C-OTDR) is proposed to accurately measure the propagation delay over a multi-span optical fiber link. The delay of the transmission fiber is measured in the reflective mode, while uni-directional node components are measured in a transmissive mode. Delimiting reflectors are required between the sections for accurate demarcation.Comment: 2019 International Topical Meeting on Microwave Photonics (MWP), Ottawa, Canad

Experimental Comparison of 56 Gbit/s PAM-4 and DMT for Data Center Interconnect Applications

Four-level pulse amplitude modulation (PAM-4) and discrete multi-tone transmission (DMT) in combination with intensity modulation and direct-detection are two promising approaches for a low-power and low-cost solution for the next generation of data center interconnect applications. We experimentally investigate and compare both modulation formats at a data rate of 56 Gb/s and a transmission wavelength of 1544 nm using the same experimental setup. We show that PAM-4 outperforms double sideband DMT and also vestigial sideband DMT for the optical back-to-back (b2b) case andalso for a transmission distance of 80 km SSMF in terms of required OSNR at a FEC-threshold of 3.8e-3. However, it is also pointed out that both versions of DMT do not require any optical dispersion compensation to transmit over 80 km SSMF while this is essential for PAM-4. Thus, implementation effort and cost may be lower for DMT. Furthermore, the dispersion tolerance of PAM-4 in dependence of a feedforward equalizer (FFE) is investigated. Four-level pulse amplitude modulation (PAM-4) and discrete multi-tone transmission (DMT) in combination with inten-sity modulation and direct-detection are two promising approaches for a low-power and low-cost solution for the next generation of data center interconnect applications. We experimentally investigate and compare both modulation formats at a data rate of 56 Gb/s and a transmission wavelength of 1544 nm using the same experimental setup. We show that PAM-4 outperforms double sideband DMT and also vestigial sideband DMT for the optical back-to-back (b2b) case and also for a transmission distance of 80 km SSMF in terms of required OSNR at a FEC-threshold of 3.8e-3. However, it is also pointed out that both versions of DMT do not require any optical dispersion compensation to transmit over 80 km SSMF while this is essential for PAM-4. Thus, implementation effort and cost may be lower for DMT. Furthermore, the dispersion tolerance of PAM-4 in dependence of a feedforward equalizer (FFE) is investigated