Fog Seeding Strategies for Information-Centric Heterogeneous Vehicular Networks

in 11th IEEE Vehicular Networking Conference (VNC 2019) (2019)

Content downloading of mobile broadband users today routinely causes network load to exceed what the Radio Access Network (RAN) can sustain without degrading user experience. Many works are therefore ... [more ▼]

Content downloading of mobile broadband users today routinely causes network load to exceed what the Radio Access Network (RAN) can sustain without degrading user experience. Many works are therefore considering edge or fog computing paradigms and Device to Device (D2D) communication using 4G/5G C-V2X or IEEE 802.11p/bd links to obtain content. When content originates (or is maintained) at a central location, however, this requires expensive seeding of the content into the mobile network. We thus advocate basing the decision of when and where to perform fog seeding on a network graph that respects connectivity metrics while performing community detection and exploiting node centrality. We present different seeding strategies and investigate their respective benefits compared to traditional information-centric networking. Using simulations, we demonstrate that choosing a suitable strategy can yield substantial benefits - and vice versa. [less ▲]

Pick the Right Guy: CQI-Based LTE Forwarder Selection in VANETs

in 8th IEEE Vehicular Networking Conference (VNC 2016) (2016, December)

Periodical collection of data from vehicles inside a target area is of interest for many applications in the context of Intelligent Transportation Systems (ITS). Long Term Evolution (LTE) has been ... [more ▼]

Periodical collection of data from vehicles inside a target area is of interest for many applications in the context of Intelligent Transportation Systems (ITS). Long Term Evolution (LTE) has been identified as a good candidate technology for supporting such type of applications - particularly for the non-safety domain. However, a high number of vehicles intermittently reporting their information via LTE can introduce a very high load on the LTE access network. In this context, the use of heterogeneous networking technologies can yield significant offloading of LTE - here, WLAN and Dedicated Short-Range Communication (DSRC) technology can support local data aggregation. In this paper, we propose an on-the-fly distributed clustering algorithm that uses both LTE and DSRC networks in the forwarder selection process. Our results clearly indicate that it is crucial to consider parameters drawn from both networking platforms for selecting the right forwarders. In particular, we show for the first time that relying on the Channel Quality Indicator (CQI) has a substantial impact. We demonstrate that our solution is able to significantly reduce the LTE channel utilization with respect to other state of the art approaches. [less ▲]

From experimental setup to bioinformatics: An RNAi screening platform to identify host factors involved in HIV-1 replication

in Biotechnology Journal (2010), 5(1), 39-49

RNA interference (RNAi) has emerged as a powerful technique for studying loss-of-function phenotypes by specific down-regulation of gene expression, allowing the investigation of virus-host interactions ... [more ▼]

RNA interference (RNAi) has emerged as a powerful technique for studying loss-of-function phenotypes by specific down-regulation of gene expression, allowing the investigation of virus-host interactions by large-scale high-throughput RNAi screens. Here we present a robust and sensitive small interfering RNA screening platform consisting of an experimental setup, single-cell image and statistical analysis as well as bioinformatics. The workflow has been established to elucidate host gene functions exploited by viruses, monitoring both suppression and enhancement of viral replication simultaneously by fluorescence microscopy. The platform comprises a two-stage procedure in which potential host factors are first identified in a primary screen and afterwards re-tested in a validation screen to confirm true positive hits. Subsequent bioinformatics allows the identification of cellular genes participating in metabolic pathways and cellular networks utilised by viruses for efficient infection. Our workflow has been used to investigate host factor usage by the human immunodeficiency virus-1 (HIV-1), but can also be adapted to other viruses. Importantly, we expect that the description of the platform will guide further screening approaches for virus-host interactions. The ViroQuant-Cell Networks RNAi Screening core facility is an integral part of the recently founded BioQuant centre for systems biology at the University of Heidelberg and will provide service to external users in the near future. [less ▲]