Experimental Demonstration of Impairment-Aware PCE for Multi-Bit-Rate WSONs
ABSTRACT In emerging multi-bit-rate wavelength switched optical networks (WSONs), the coexistence of lightpaths operating at different bit-rates and modulation formats (e.g., based on amplitude and phase modulation) induces relevant traffic dependent detrimental effects that need to be considered during impairment-aware routing and wavelength assignment (IA-RWA). The considerable complexity of IA-RWA computation has driven the Internet Engineering Task Force (IETF) to propose specific path computation element (PCE) architectures in support of IA-RWA for WSONs. In this paper, following the IETF indications, we expand two PCE architectures and experimentally evaluate five different PCE architectural solutions, performing either combined or separated impairment estimation and RWA, with on-line and off-line computation of impairment validated paths, and with the possible utilization of a novel PCE Protocol (PCEP) extension. Results in terms of traffic engineering performance, path computation delivery time and amount of exchanged PCEP messages are reported and discussed to highlight the benefits and application scenarios of the considered PCE architectures.
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ABSTRACT: A Mixed Line Rate (MLR) optical network is a good candidate for a core backbone network because of its ability to provide diverse line rates to effectively accommodate traffic demands with heterogeneous bandwidth requirements. Because of the deleterious effects of physical impairments, there is a maximum transmission reach for optical signals before they have to be regenerated. Being expensive devices, regenerators are expected to be sparsely located and used in such a network, called a translucent optical network. In this paper, we consider the Grooming, Routing, and Wavelength Assignment (GRWA) problem so that the Quality of Transmission (QoT) for connections is satisfied, and the network-level performance metric of blocking probability is minimized. Cross-layer heuristics to effectively allocate the sparse regenerators in MLR networks are developed, and extensive simulation results are presented to demonstrate their effectiveness.Wireless Communication over ZigBee for Automotive Inclination Measurement. China Communications 01/2013; 10(1):17-30. · 0.46 Impact Factor
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ABSTRACT: With increasing energy consumption of the Internet, it is now imperative to design energy-efficient network architectures and protocols. Optical technologies have significant promise in improving the energy efficiency of network infrastructures. Future optical backbone networks will be heterogeneous in nature where a single link may carry various line-rate signals. This mixed-line-rate (MLR) network architecture is shown to be cost effective in satisfying heterogeneous traffic demands. In this study, we present mathematical models that can act as references for designing energy- and cost-efficient MLR optical networks. We also perform a comparative study of the energy efficiency of MLR and special cases of MLR design, named as single-line-rate networks (where all the links have same line rates). We explore the scenarios where the MLR networks minimize energy consumption. Finally, we investigate the relationship between energy-minimized and cost-minimized MLR network design.Journal of Lightwave Technology 01/2012; 30(1):130-139. · 2.56 Impact Factor
Conference Paper: Impairment-aware lightpath provisioning in mixed line rate networks[Show abstract] [Hide abstract]
ABSTRACT: In mixed line rate (MLR) networks, different line rates can coexist on the same fiber, on different wavelengths. Each lightpath can be established end-to-end, with requested line rate. Advanced modulation techniques are required for high line rates. Signals being propagated over transparent paths are exposed to detrimental effects of physical layer impairments (PLI). Advanced modulation techniques are more susceptible to impairments, especially to the cross-phase modulation (XPM) induced by intensity-modulated channels. In this study, we investigate the impairment-aware lightpath provisioning problem for MLR networks. We consider a transparent optical network where we aim to maximize the number of established connections, while avoiding disruption of existing lightpaths. We propose a weighted approach for impairment-aware lightpath provisioning in MLR networks. We employ an auxiliary graph to capture the PLIs on differently modulated channels with a weight assignment scheme. Simulation results show that the performance of our approach is noteworthy, in terms of blocking probability, bandwidth blocking ratio, and resource consumption.Advanced Networks and Telecommuncations Systems (ANTS), 2012 IEEE International Conference on; 01/2012