Energy efficiency considerations in integrated IT and optical network resilient infrastructures

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources

A Flow-aware MAC Protocol for a Passive Optical Metropolitan Area Network

The paper introduces an original MAC protocol for a passive optical metropolitan area network using time-domain wavelength interleaved networking (TWIN)% as proposed recently by Bell Labs . Optical channels are shared under the distributed control of destinations using a packet-based polling algorithm. This MAC is inspired more by EPON dynamic bandwidth allocation than the slotted, GPON-like access control generally envisaged for TWIN. Management of source-destination traffic streams is flow-aware with the size of allocated time slices being proportional to the number of active flows. This emulates a network-wide, distributed fair queuing scheduler, bringing the well-known implicit service differentiation and robustness advantages of this mechanism to the metro area network. The paper presents a comprehensive performance evaluation based on analytical modelling supported by simulations. The proposed MAC is shown to have excellent performance in terms of both traffic capacity and packet latency

R&D Cooperation and Innovation Activities of Firms - Evidence for the German Manufacturing Industry -

The aim of the paper is to investigate in a simultaneous equation framework the role of R&D cooperation in the innovation process under two specific aspects. First, the analysis is concentrated on the impact of R&D cooperation - in line with other factors - on firm's innovation input and output. Second, it will be analyzed how the number of cooperation partners affects the development of new products. Starting with the discussion of theoretically expected effects of successfully R&D cooperation on the innovation activities of firms, the importance of inter-organizational arrangements in R&D is empirically investigated for firms in the German manufacturing industry. The estimation results can be summarized as follows: In the German manufacturing industry, R&D cooperations are used complementary in the innovation process, enhancing the innovation input and output of firms measured by the intensity of inhouse R&D respectively the realization of product innovations. On the input side, the intensity of inhouse R&D also stimulates the probability and the number of R&D cooperations with other firms and institutions.R&D cooperation, innovation behaviour, technological opportunities, manufacturing industry