Eduard Hasenleithner

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This paper focuses on the traffic composition in a real GPRS/UMTS network. We present results from two datasets covering two one-week measurement periods, in December 2004 and November 2005. We show how users and traffic split between access technologies (GPRS and UMTS) and services, and present an analysis of the per-user activity at the PDP-context level.(More)
This paper proposes an algorithm to identify TCP spurious retransmission timeouts by post processing of packet traces monitored in operational networks. The operational principles of the algorithm and the assumptions behind its design are explained in detail as well as the situations in which the algorithm is prone to inaccuracies. By extensive measurements(More)
The presence of "unwanted" (or background) traffic in the Internet is a well-known fact. In principle any network that has been engineered without taking into account the presence of unwanted traffic might experience troubles during periods of massive exposure to it, e.g. large-scale infections. A concrete example was provided by the spreading of(More)
We consider the optimization of the Core Network section of a mobile cellular network. While we focus on GPRS the proposed method can be applied to UMTS as well. The problem is to find an optimal assignment of PCUs (Packet Control Units, a module of the BSC) to SGSNs based on measured data. Two concurrent optimization goals apply: balance the number(More)
The availability of synchronized packet-level traces captured at different links allows the extraction of one-way delays for the network section in between. Delay statistics can be used as quality indicators to validate the health of the network and to detect global performance drifts and/or localized problems. Since packet delays depend not only on the(More)
Users expect mobile Internet access via 3G technologies to be comparable to wired access in terms of throughput and latency. HSPA achieves this for throughput, whereas delay is significantly higher. In this paper we measure the overall latency introduced by HSUPA and accurately dissect it into contributions of USB-modem (UE), base station (NodeB) and(More)
A 3G network is a magnificently complex object embedded in a highly heterogeneous and ever-changing usage environment. It combines the functional complexity of the wireless cellular paradigm with the protocol dynamics of TCP=IP networks. Understanding such an environment is more urgent and at the same time more difficult than for legacy 2G networks.(More)
Flow size based congestion control has the potential to improve user perceived Web performance due to the heavy tailed characteristic of file size distributions in the Web. After discussing the benefits and drawbacks of transport protocol and router based solutions for size based congestion control, guidelines for algorithm design are developed. Using these(More)