Scientific posters authored by PhD Students and Internship Students from IMDEA Networks will be exhibited during the workshop.

Poster: "Context-awareness for IoT Networks" 

PhD Student: Amr AbdelKhalek Abdelnabi

Supervisor: Vincenzo Mancuso

Abstract: 

IoT is expected to have 50 billion connected objects by 2020. Objects will use a pletora of heterogeneous networks and protocols, so that the deployment of a global IoT system will face serious challenges with respect to interoperability, scalability, mobility, security and energy. However, since IoT systems are based on two main functions, namely contextualization and networking, we propose to use the rich context information that can be gathered by sensors within the contextualization function to adapt the networking function, and specifically the communication protocols. We propose to implement software agents operating as actuators. Such communication actuators would offer the possibility to dynamically deploy network infrastructures and services on demand and to address the above mentioned IoT challenges under the control of a context-aware middleware. We use an application for environmental monitoring and dynamic surveillance network deployment to illustrate our proposal.

[ PDF  631 Kb]

Poster: “Performance analysis of IEEE 802.11ad in large scale deployments through experiments and simulations”

PhD Student: Hany Assasa

Supervisor: Joerg Widmer

Abstract:

Millimeter-wave technology is one of the main pillars of the future wireless networks. The main reason lies in the quantum leap of capacity it provides with respect to wireless networks operating in the sub 6-GHz band. Nevertheless, efficient and reliable communication in this band demands novel techniques to tackle all the associated barriers related to wireless propagation in those bands. In this poster, we present the extension of our ns-3 IEEE 802.11ad model with new techniques, including dynamic and static channel access schemes, decentralized clustering, beamformed link maintenance, spatial sharing, and half-duplex relay operation as defined in the IEEE 802.11ad amendment. In addition, we present our large deployment testbed for 60 GHz networks based on the TALON router with custom firmware.
We use this testbed to study IEEE 802.11ad MAC layer efficiency, interference, spectrum sharing, spatial sharing, and multi-AP deployment issues.

[ PDF  794 Kb]

Poster: "Multi-Path D2D Leads to Satisfaction"

PhD Student: Edgar Arribas

Supervisor: Vincenzo Mancuso

Abstract:

Device-to-Device (D2D) communications potentially allow users placed in a cell to establish direct connections among them using several connection modes. We propose Multi-Path D2D (MPD2D) as a mathematical optimisation framework that accounts for the availability of D2D modes under flow demand requirements. MPD2D selects the combination of cellular and D2D links that fits better for boosting the network benefit. We consider the Underlay and Overlay as Inband D2D modes over cellular technology (LTE) and the Outband D2D mode exploiting WLAN technology (WiFi). Throughput, energy consumption, interference, and flow requirements are managed in order to maximise a network utility function accounting for cell capacity and power efficiency. We also derive a user satisfaction metric that accounts for the history of users within the cell. Integrating such a metric is lightweight yet very effective to drive towards almost complete fairness for the system over time. Our optimisation scheme is formulated as a Binary Non-Linear Program which results in very high performance in terms of throughput gain in comparison to other benchmarks for the D2D mode selection problem. Finally, we propose two effective heuristics whose performance and complexity we compare with optimal results and that largely outperform state of the art solutions.

[ PDF  735 Kb]

Poster: "Extending range and mobility of 60 GHz networks"

PhD Student: Guillermo Bielsa

Supervisor: Joerg Widmer

Abstract:

Millimeter-wave communications are being considered for 5G networks. In this poster we compare the performance of 60GHz links in static and mobile environments using commercial off-the-shelf devices. We observe frequent link breaks in case of node mobility, which suggests that further research on better beam-training mechanisms for mobility is required. In parallel, we perform a study of the frequency selectivity of 60GHz channels, and show their behaviour for different techniques such as bitloading, subcarrier switch-off, and waterfilling. We show that such techniques can allow a range extension of up to 100%

[ PDF  877 Kb]

Poster: “Mobile CDN strategies”

Internship Student: Hossein Doroud

Supervisor: Narseo Vallina-Rodríguez

Authors: Hossein Doroud, Foivos Michelinakis, Abbas Razaghpanah, Andra Lutu, Narseo Vallina Rodriguez, Phillipa Gill, Joerg Widmer

Poster: "Single-anchor model-based acoustic range estimation and localization in shallow waters"

PhD Student: Elizaveta Dubrovinskaya

Supervisor: Paolo Casari

Abstract:

In recent decades, the exploration of relatively shallow waters has been vested with great interest both by the academia and by ocean industries. A significant challenge to be solved in this respect is how to accurately navigate autonomous underwater vehicles (AUV).
As the underwater environment absorbs radio waves and imposes a slow, non-linear multipath propagation on typically used acoustic signals, GPS-like approaches become inconvenient.
Most of the research in the field of underwater localization and tracking focuses on complex positioning solutions that require multiple sensors and hydrophones: these approaches are not desirable, given that low energy consumption and efficient bandwidth utilization are key design constraints for underwater networks. In this poster we consider range estimation and localization in passive underwater systems with a single anchor point, and propose two methods that take advantage of additional environmental information to improve the ranging and localization performance. The accuracy of range estimation can be improved by measuring the deviation between (theoretical) rectilinear and actual sound wave propagation trajectories and using this deviation to correct wrong range estimates. If the knowledge about the environment includes variable bathymetry and sound speed profile, it becomes possible to actually localize a node. Specifically, by correlating channel estimates from actual received signals with expected channel impulse responses obtained from a model, we can estimate not only the range of a node with respect to the anchor, but also the angle of arrival, and hence the position of the node. 
The performed simulations on sensitivity to the errors in input data and environmental characteristics prove the correctness and functionality of the proposed approaches for underwater positioning.

[ PDF  1 Mb]

Poster: “Hybrid and Autonomous Time-of-Flight Positioning System”

PhD Student: Aymen Fakhreddine

Supervisor: Domenico Giustiniano

Authors: Aymen Fakhreddine, Domenico Giustiniano, Vincent Lenders

Poster: “Follow that Light: Leveraging LEDs for Relative Two-Dimensional Localization”

PhD Student: Ander Galisteo

Supervisor: Domenico Giustiniano

Poster: "Benefits from Incremental Deployment of Inter-Domain Routing Protocols"

PhD Student: Vadim Kirillin

Supervisor: Sergey Gorinsky

Abstract:

While many inter-domain protocols have been proposed with a promise to improve routing performance, they struggle to get widely deployed. Because about 50,000 independent Autonomous Systems operate the Internet communication infrastructure, their simultaneous adoption of a new routing protocol is highly unlikely. In this work, we analyze how routing performance changes with incremental deployment. We model a protocol via the amount and relevance of routing-metric information it provides to individual nodes: whereas every node with the incumbent protocol knows imprecisely the distributions of metric values for the other nodes, each of the nodes adopting the new protocol almost surely knows the distributions of their metric values. We formulate traffic routing as an optimization problem and analytically show that the routing cost depends smoothly on its solutions. Then, using simulations with realistic topologies and traffic, we show that routing performance improves smoothly, without a threshold, as the number of adopting nodes increases. This result indicates that a significant adoption is needed to yield a substantial fraction of the performance benefits.

[ PDF  555 Kb]

Poster: "JADE: Zero-Knowledge Device Localization and Environment Mapping for Millimeter Wave Systems"

PhD Student: Joan Palacios

Supervisor: Joerg Widmer

Abstract:

Device localization is a highly important functionality for a range of applications. It is particularly beneficial in mmWave networks, where it can be used to reduce the beam training overhead and anticipate handovers between access points. In this paper, we present JADE, an algorithm that estimates the location of a mobile user in an indoor space without any knowledge about the surrounding environment (floor plan, location of walls and presence of reflective surfaces) or about the location and number of access points available therein. JADE leverages the beam procedure used in pre-standard and commercial mmWave equipment to estimate the angle-of-arrival of multipath components of the signal sent by visible access points. This information is then employed to localize the mobile user, estimate the position of access points and finally form a map of the environment. No radar-like ranging operations are required for this. Our results demonstrate that JADE can localize a user with sub-meter accuracy in the broad majority of the cases, and that it even outperforms localization algorithms that require full knowledge of the environment and access point positions.

[ PDF  1 Mb]

Poster: "On the persistence of wireless advertising without infrastructure support"

PhD Student: Noelia Pérez

Supervisor: Vincenzo Mancuso

Abstract:

The number of devices connected to the Internet keeps growing, and the traffic they collectively generate grows even faster, creating congestion issues, especially in the network access segment. Some of the newer Internet applications can however be served with device-to-device (D2D) opportunistic communications, thus offloading a portion of the traffic from the network. In this work we study and experiment the possibility of providing content availability to end user terminals by exploiting D2D infrastructureless connectivity and opportunistic communication. We have implemented an Android application that supports infrastructureless distributed content sharing between wireless devices using Wi-Fi Direct. We collected experimental data, which allow us to analyze the occurring events and to assess and compare the performance of our service against existing communication protocols.

[ PDF  1 Mb]