Abstract. In this paper we propose the concept of an end-to-end (e2e) SelfProtecting Multi-Path (SPM) as a protection switching mechanism that may be implemented, e.g., in Multiprotocol Label Switching (MPLS) networks. In case of local outages, resilient networks redirect the traffic from a failed link over an e2e backup path to its destination. In this case, Quality of Service (QoS) can only be provided if sufficient extra capacity is available. If backup capacity can be shared among different backup paths, multi-path routing allows for considerable savings regarding this extra capacity. The SPM consists of disjoint paths that carry the traffic bothin normal operation mode and during local outages. If a partial path is affected by a network failure, the traffic is just distributed to the remaining working paths. This structure is easy to configure and the switching to failure mode operation is simple since no signalling is required. Based on analytical results, we show that Ioad balancing of the traffic across the disjoint paths can reduce the required backup capacity significantly. The backup performance depends strongly on the network topology, and the SPM outperforms simple Open Shortest Path First (OSPF) rerouting by far.

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Abstract. Network Virtualization Environments have great potential for overcoming the current ossification of the Internet, fostering innovation, and allowing several concurrent architectures to run on the same physical network. This paper presents a novel physically inspired algorithm for efficiently solving the virtual network embedding problem of placing a virtual network over a substrate network. Compared to a reference heuristic, our algorithm shows lower rejection rates and improved substrate network utilization.

Abstract-Orthogonal Frequency Division Multiple Access (OFDMA) is the basis for several emerging wireless systems, such as 802.16e (WiMAX) or 3GPP Long Term Evolution (LTE). In OFDMA, different users are multiplexed in time and frequency. In the 802.16e Adaptive Modulation and Coding (AMC) downlink, the data bursts for a particular terminal have a rectangular shape and need to be placed in the two-dimensional time/frequency plane. The position and shape of the rectangles is arbitrary, and it is the task of the frame packer to pack the frame efficiently, wasting as little space as possible. In this paper, we treat the frame packing problem as a strip-packing problem. We solve this combinatorial optimization problem by developing a suitable representation for a genetic algorithm. This algorithm can reach within 5% of the theoretical lower bound for the packing efficiency.