In this paper we present a novel approach to assess the impact of new and existing services on traffic volume in current and future backbone networks. Several proposals to model traffic load in access and backbone networks exist in the literature. These proposals consider current Internet traffic like http, smtp, ftp and Peer-to-Peer (P2P). We expect, however, that there will be a change in traffic load for future networks caused by services like IP Television (IPTV), Video on Demand (VoD) and Virtual Private Networks (VPN). Additionally, population-based models may no longer be applicable due to the widespread use of service-providers and hierarchical routing through network peering points. Therefore, it is important to reassess future traffic volumes and traffic patterns and to identify those services that have the most impact on the networks. We model today's traffic volume of each of the described services and estimate future traffic volumes taking peering points into account. To illustrate the different traffic flows and to characterise the traffic distribution we apply our results to a Germany reference network.
In a typical plug-in hybrid electric vehicle (PHEV) installation, there exist multiple, potentially separate, cooling circuits. These circuits may have individual cooling/heating requirements or they may have common aspects. Opportunities exist for combining circuits for series applications for cost, weight and efficiency benefits. However, careful consideration must be paid to the compatibility of these circuits both in terms of temperature range requirements, but also in terms of the thermal loading of the systems on the cooling circuits. This paper presents details of a cooling system for a PHEV demonstrator recently completed by MAHLE Powertrain. The opportunities for the integration of several cooling circuits, including the cabin heating, ventilation and airconditioning (HVAC) system, to optimise the system from a cost, package-space and weight perspective are discussed. Furthermore, the opportunities for the preconditioning and operating strategies for the complete cooling/heating system, from a holistic vehicle efficiency perspective, are also briefly outlined.
The enormous growth of bandwidth needs and the constant revenues of the carriers at the same time require the introduction of packet technologies in transport networks. The extension of Ethernet with carrier-grade features is a promising approach to provide necessary characteristics like scalability, quality of service, and operations, administration, and maintenance. Interesting technological aspects are multi-layer and multi-domain operation of these packet transport networks and their control via Generalized MPLS. A possible solution can be seen in a function split where IP stays the convergence platform for applications and services and Ethernet becomes the convergence platform for transport.
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