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Item type:Publication, Access status: without files , Scylla: interleaving multiple IoT stacks on a single radio(Association for Computing Machinery (ACM), 2018-12); ; ; Uzmi, Zartash AfzalIoT deployments often require communication between devices that employ heterogeneous wireless technologies. Traditionally, expensive gateways are used to relay packets between heterogeneous nodes. Recent cross-technology communication offers a low bandwidth alternative, which is only feasible when communication between such nodes is limited to simple binary commands. In contrast, our work capitalizes on the increasing presence of multi-standard radio chips in mainstream IoT devices, to provide a new perspective on how to enable direct communication between heterogeneous nodes. We design Scylla—a software control layer—that allows multiple wireless stacks to coexist on top of a single radio chip, thereby simultaneously offering multiple communication interfaces. Uniquely, Scylla achieves near stack-native performance and requires no changes to the standards.Publicationtype: Conference Paper14 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Poster abstract: taming link-layer heterogeneity in IoT through interleaving multiple link-layers over a single radio(Association for Computing Machinery (ACM), 2017-11); ; We propose dynamic reconfiguration of the radio interface in IoT platforms to support multiple link layers simultaneously. This allows us to tackle the increasing link layer heterogeneity in IoT devices, thus bringing a multitude of benefits: extensible and vender agnostic multihop deployments, rapid integration of the new “things” into an existing network, as well as seamless integration of the IoT with the traditional wireless Internet.Publicationtype: Conference Paper10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Modular remote reprogramming of sensor nodesWireless sensor networks are envisioned to be deployed in the absence of permanent network infrastructure and in environments with limited or no human accessibility. Hence, such deployments demand mechanisms to remotely (i.e., over the air) reconfigure and update the software on the nodes. In this paper we introduce DyTOS, a TinyOS based remote reprogramming approach that enables the dynamic exchange of software components and thus incrementally update the operating system and its applications. The core idea is to preserve the modularity of TinyOS, i.e., its componentisation, which is lost during the normal compilation process, and enable runtime composition of TinyOS components on the sensor node. The proposed solution integrates seamlessly into the system architecture of TinyOS: It does not require any changes to the programming model of TinyOS and all existing components can be reused transparently. Our evaluation shows that DyTOS incurs a low performance overhead while keeping a smaller - up to one third - memory footprint than other comparable solutions.Publicationtype: Journal Article12 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Exploiting the burstiness of intermediate-quality wireless links(2012-04-19); ; We address the challenge of link estimation and routing over highly dynamic links, thats is, bursty links that rapidly shift between reliable and unreliable periods of transmissions. Based on significant empirical evidence of over 100,000 transmissions over each link in 802.15.4 and 802.11 testbeds, we propose two metrics, expected future transmissions (EFT) and MAC3, for runtime estimation of bursty wireless links. We introduce a bursty link estimator (BLE) that based on these two metrics, accurately estimates bursty links in the network rendering them available for data transmissions. Finally, we present bursty routing extensions (BRE): an adaptive routing strategy that uses BLE for forwarding packets over bursty links if they offer better routing progress than long-term stable links. Our evaluation, comprising experimental data from widely used IEEE 802.15.4-based testbeds, reveals an average of 19 and a maximum of 42 reduction in the number of transmissions when routing over long-range bursty links typically ignored by routing protocols. Additionally, we show that both BLE and BRE are not tied to any specific routing protocol and integrate seamlessly with existing routing protocols and link estimators.Publicationtype: Journal Article25 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Probabilistic addressing: Stable addresses in unstable wireless networks(IEEE, 2011-06-23); ; 9 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Tools and modeling approaches for simulating hardware and systemsDue to its high level of abstraction, flexibility and scalability network simulation is the standard means for the evaluation of distributed systems. Its abstraction from implementation details such as target platforms, operating systems and devices limits the impact of system artifacts and allows a researcher to solely focus on algorithmic challenges. © 2010 Springer-Verlag Berlin Heidelberg.Publicationtype: Book part15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , KleeNet: Discovering insidious interaction bugs in wireless sensor networks before deployment(Association for Computing Machinery (ACM), 2010-07-16); ; 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Statistical vector based point-to-point routing in wireless networks(2010-07-16); ; 12 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Dynamic TinyOS: Modular and transparent incremental code-updates for sensor networksLong-term deployments of sensor networks in physically inaccessible environments make remote re-programmability of sensor nodes a necessity. Ranging from full image replacement to virtual machines, a variety of mechanisms exist today to deploy new software or to fix bugs in deployed systems. However, TinyOS - the current state of the art sensor node operating system - is still limited to full image replacement as nodes execute a statically-linked system-image generated at compilation time. In this paper we introduce Dynamic TinyOS to enable the dynamic exchange of software components and thus incrementally update the operating system and its applications. The core idea is to preserve the modularity of TinyOS, i.e. its componentization, which is lost during the normal compilation process, and enable runtime composition of TinyOS components on the sensor node. The proposed solution integrates seamlessly into the system architecture of TinyOS: It does not require any changes to the programming model of TinyOS and existing components can be reused transparently. Our evaluation shows that Dynamic TinyOS incurs a low performance overhead while keeping a smaller - up to one third - memory footprint than other comparable solutions.Publicationtype: Conference Paper45 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Promoting power to a first class metric in network simulationsAccurate prediction of energy consumption early in the design process is essential to efficiently optimize algorithms and protocols. However, despite energy efficiency gathering significant attention in networking research, limited effort has been invested in providing requisite evaluation tools and models. Hence, developers demand powerful evaluation tools to assist them in comparing new communication paradigms in terms of energy efficiency, and minimizing the energy requirements of algorithms. In this paper, we argue for promoting energy to a first class metric in network simulations. We explore the challenges involved in modelling energy in network simulations and present a detailed analysis of different modelling techniques. Finally, we discuss their applicability in high-level network simulations.Publicationtype: Conference Paper14