Sascha Gübner

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In this paper, we present a measurement study of the multi-hop behavior of the new IEEE 802.11n standard in an indoor mesh testbed. As main contribution, we quantitatively describe characteristics of IEEE 802.11n on multi-hop paths like throughput, aggregate size and utilized MIMO features. Furthermore, we show how to build an IEEE 802.11n indoor testbed(More)
In this paper we characterize the effective throughput for multi-hop paths in IEEE 802.11n based wireless mesh networks. We derive an analytical model capturing the effects of frame aggregation and block acknowledgements, features found in the new IEEE 802.11n standard. We describe the throughput at MAC layer as a function of bit error rate, aggregation(More)
In this paper, we study the effects of frame aggregation on video streaming performance in a real-world IEEE 802.11n testbed. We quantitatively characterize delay, video quality, and mean aggregate size in two multi-hop scenarios. We observe that streaming applications naturally take advantage of frame aggregation, both in single- and multi-stream(More)
We present an analytically tractable mathematical approach for accurately modeling the distribution of inter-contact times between mobile devices carried by users. The contribution of this paper is two-fold: (1) we show how to employ a Markov-modulated Poisson process (MMPP) for characterizing long-term dependencies in the mobility behavior, and (2) we(More)
In this paper, we introduce and evaluate CrossTrace, a framework for performing cross-layer measurements in IEEE 802.11 based wireless networks. CrossTrace allows tracing of parameters at MAC-, routing and transport layer in a controlled environment and in a repeatable manner. Using CrossTrace, we conduct a comprehensive measurement study in a miniaturized(More)
Recently, two trends in wireless communication are observable. First, traffic patterns tend to be unsaturated, due to an enormous increase of traffic types like mobile video and voice streaming. Second, new standards like IEEE 802.11n or IEEE 802.11ac allow huge physical data rates up to several Gbit/s. However, to utilize these data rates an efficient(More)
Satellites are specifically made for telecommunication purpose. In satellite systems, On-Board communication is a one of the key aspect in which transfer of digital data (high speed high volume data) & TM-TC (Tele command or Telemetry, low volume low speed data) is taking place. Data communication among satellite systems also known as Inter-Satellite(More)
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