IBM POWER5e systems combine enhancements in the IBM PowerPCe processor architecture with greatly enhanced firmware to significantly increase the virtualization capabilities of IBM POWERe servers. The POWER hypervisor, the basis of the IBM Virtualization Enginee technologies on POWER5 systems, delivers leading-edge mainframe virtualization technologies to the UNIXtmarketplace. In addition to bei...

Virtual network mapping (VNM) is to build a network on demand by deploying virtual machines in a substrate network, subject to constraints on capacity, bandwidth and latency. It is critical to data centers for coping with dynamic cloud workloads. This paper shows that VNM can be approached by graph pattern matching, a well-studied database topic. (1) We propose to model a virtual network reques...

The past few years have seen a rise in popularity of massively parallel architectures that use fat-trees as their interconnection networks. In this paper we study the communication performance of a parametric family of fat-trees, the k-ary n-trees, built with constant arity switches interconnected in a regular topology. Through simulation on a 4-ary 4-tree with 256 nodes, we analyze some varian...

The past few years have seen a rise in popularity of massively parallel architectures that use fat-trees as their interconnection networks. In this paper we study the communication performance of a parametric family of fat-trees, the k-ary n-trees, built with constant arity switches interconnected in a regular topology. Through simulation on a 4-ary 4-tree with 256 nodes, we analyze some varian...

Virtual network mapping (VNM) is to build a network on demand by deploying virtual machines in a substrate network, subject to constraints on capacity, bandwidth and latency. It is critical to data centers for coping with dynamic cloud workloads. This paper shows that VNM can be approached by graph pattern matching, a well-studied database topic. (1) We propose to model a virtual network reques...

Accurate and tractable channel modeling is critical to realizing the full potential of antenna arrays in wireless communications. In this paper we propose a framework for modeling multi-antenna multipath channels based on the notion of virtual spatial angles. The virtual angles are xed a priori and are determined by the number of antennas at the transmitter and receiver and the spacing between ...

In this paper we deal with planning and optimization of survivable WDM networks. We investigate routing and planning of working and spare capacity for Wavelength Path and Virtual Wavelength Path networks. Models for recommendation of k diversified paths and diversified path restoration for WDM networks are presented. The results show the dependency of spare capacity cost from number of k recomm...

We propose an iterative algorithm for the Virtual Topology Design (VTD) in optical networks. The algorithm eliminates lighter traffic lightpaths and re-arrange the traffic through the remaining lightpaths. This tries to preserve the open capacity for the accommodation of future unknown demands. The results suggest that it is feasible to preserve enough open capacity to avoid blocking of future ...