Unbundling in Current Broadband and Next-Generation Ultra-Broadband Access Networks

This article overviews the methods that are currently under investigation for implementing multi-operator open-access/shared-access techniques in next-generation access ultra-broadband architectures, starting from the traditional "unbundling-of-the-local-loop" techniques implemented in legacy twisted-pair digital subscriber line access networks. A straightforward replication of these copper-based unbundling-of-the-local-loop techniques is usually not feasible on next-generation access networks, including fiber-to-the-home point-to-multipoint passive optical networks. To investigate this issue, the article first gives a concise description of traditional copper-based unbundling-of-the-local-loop solutions, then focalizes on both next-generation access hybrid fiber-copper digital subscriber line fiber-to-the-cabinet scenarios and on fiber to the home by accounting for the mix of regulatory and technological reasons driving the next-generation access migration path, focusing mostly on the European situation. © 2014 Taylor and Francis Group, LLC

DesignCon 2010 Timing Measurement Problems and Solutions in Source Terminated Memory Systems with Inaccessible Probing Points

Abstract This paper discusses the common problem of making setup and hold measurements in memory systems where the desired probing point is inaccessible. Timing measurement problems of this type are problematic not only in skew due to incorrect probing locations, but also due to waveform distortions due to reflections created by various termination schemes. The paper considers various problems specifically in termination methods utilized in memory systems and offers some solutions and methods for mitigating measurement problems. A real-life example in a QDR memory system is used