Giorgio Cazzaniga

Synchronization techniques in backhauling networks

Synchronization in transport networks was a hot topic for telecom in early 90s with the advent of SDH, replacing PDH. When packet networks and the Internet began to spread, it subsided for some years, until mobile technologies evolved from TDM (2G) to packets (3G, 4G). Nowadays the transport of frequency and time over transport networks is one of the most debated topics both in the industry and within international standard bodies, presenting several challenging aspects that even tend to multiply as new technologies not originally thought to carry synchronization are used for mobile backhauling, ranging from packets (L2 and L3), to TDM and WDM (OTN, CPRI). In this paper we analyse from a technical and economical point of view common problems and solutions related to the transport of frequency and time across several types of TDM and packet networks, summarizing latest research results, open issues and possible directions for evolution.

A new perspective on burst-switched optical networks

Recent experimental research in coherent detection has enabled 100G (or higher bit-rate) optical receivers to switch between wavelengths in less than a hundred nanoseconds. Such technologies enable a novel variant of the Time-domain Wavelength Interleaved Networks (TWIN) architecture in which fast tunable receivers replace tunable transmitters as the main switching elements in the otherwise passive optical network. Similar to TWIN, this architecture enables efficient sharing of 100G (or higher) wavelength rates among multiple destinations in metro networks or data centers where individual node-pairs may not need the full capacity of each wavelength. In this paper, we present the key elements of this novel variant of TWIN, discuss framing and scheduling efficiency, sub- and super-framing for TDM and packet data, as well as protection mechanisms. We also present the benefit of this approach relative to other optical network technologies. We conclude with an overview of the potential applications of this novel optical networking architecture.