Fast Resilience Research Articles

RINGOSTAR: an evolutionary performance-enhancing WDM upgrade of IEEE 802.17 resilient packet ring

To upgrade IEEE 802.17 Resilient Packet Ring networks by WDM, most previously reported approaches deploy WDM on the ring, requiring modifications of all nodes at the architecture and/or protocol level without significantly enhancing the performance of RPR apart from increased capacity and optical bypassing capability. In this article we aim at rethinking the box. Leveraging on the dark fiber infrastructure abundantly available in today's metropolitan areas, a subset of RPR nodes are interconnected by a single-hop star WDM subnetwork in a pay-as-you-grow manner. Building on RPR's destination stripping, wrapping, and steering techniques, we describe and examine two novel evolutionary performance-enhancing techniques: proxy stripping and protectoration. Our findings show that the resultant RINGOSTAR network not only dramatically increases spatial reuse, provides fairness as well as fast and efficient resilience against multiple failures but also supports both metro core's uniform and in particular metro edge's strongly hubbed traffic in a highly efficient way

A practical course in digital video communications based on MATLAB

The outline of new course in video coding is presented in which the basic concepts are reinforced by way of a series of graded MATLAB exercises. Following a brief overview of the motion-compensated discrete cosine transform (DCT) encoder, a number of exercises are described in which the student obtains an understanding of image correlations and entropy and the concepts involved in predictive encoding. The data compaction properties of the discrete cosine transform are then illustrated together with interframe motion-estimation and motion-compensated prediction. All aspects of the evolving video encoder are then integrated by way of a simplified encoder syntax that is based upon the standard Moving Picture Experts Group (MPEG) syntax. This allows students to exchange digital bit-streams and decode image sequences that have been encoded by fellow students. Advanced topics such as fast motion estimation techniques, error resilience, and other coding approaches are briefly discussed.