Embedded sensor systems are well suited to provide context data, i.e. any information which allows determining the context of entities (e.g. a user's location, an object's environmental parameters, or the number of people in a room). The additional integration of actuators allows interaction with the real world, e.g. control of heating, ventilation, or lighting. However, the big gap between the heterogeneous set of devices providing sensing and/or actuation needs to be bridged to enable smart context-aware applications. Special consideration hereby needs to be given to the efficient use of the available energy budget and the support for device heterogeneity. In this talk, means towards energy-efficient data transfer by applying header and payload compression for Wireless Sensor and Actuator Networks (WSAN) are presented, as well as our approach towards the seamless integration of WSAN nodes through using semantic self-descriptions and means towards unifying the access to node resources.  

IMDEA Networks is organizing its 2nd Annual International Workshop, this year focusing on Energy Efficiency and Networking on 31st May – 1st June, 2010 in Madrid, Spain. The workshop will include presentations and a panel dealing with the latest advances and challenges facing the field. Energy efficiency is becoming one of the most important issues of our time. Population growth and exhaustion of available energy sources makes clever use of energy one of the main challenges for our society. The objective of this workshop is to explore the role of networking in the general effort towards sustainable use of energy.

Users' demands for Internet connectivity anytime anywhere are no longer a future requirement, but a reality that operators face today. The current trend in hand-held devices, equipped with multiple access technologies, and accessing IP data services triggered the need for mobility support managed by the IP layer. However, the complexity of protocols such as Mobile IP complicated the deployment of solutions in real products. Lately, there is a new trend toward solutions that enable the mobility of IP devices with a local domain with only the support from the network. Proxy Mobile IPv6 is the solution standardized by the IETF that follows this "novel" approach.

Why should I consider a future in research? What sort of opportunities does a PhD open up for me? What makes research in the science of networks such an exciting career choice? How can we ensure that the Internet can grow and adapt to ever-changing needs over the coming decades? What lies beyond the Internet? What inspires network research?

A sensor is a device capable of monitoring physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. Sensor networks composed of hundreds, or sometime of thousands of nodes, are able to gather large quantities of information enabling dynamic large scale surveillance applications to be deployed. Most of surveillance applications have a high level of criticality and can not be deployed with the current state of technology. Besides military applications that possess an obvious criticality level and have a very specific usage, surveillance applications oriented toward Critical Infrastructures and disaster relief are also very important applications that many countries have identified as critical in the near future. In this presentation, we will present the challenges in deploying mission-critical surveillance applications and will present our latest works on criticaity modeling and management.

Despite the broadly title, the seminar will be focused in the notion of max-min fairness (MMF) and its application to routing optimization in communication networks: 1. Basic notions 2. Convex MMF problems 3. Non-convex MMF problems 4. Examples of MMF routing optimization problems

The optimal configuration of the contention parameters of a WLAN depends on the network conditions in terms of number of stations and the traffic they generate. Following this observation, a considerable effort in the literature has been devoted to the design of distributed algorithms that optimally configure the WLAN parameters based on current conditions. In this work we propose a novel algorithm that, in contrast to previous proposals which are mostly based on heuristics, is sustained by mathematical foundations from multivariable control theory. A key advantage of the algorithm over existing approaches is that it is compliant with the 802.11 standard and can be implemented with current wireless cards without introducing any changes into the hardware or firmware. We study the performance of our proposal by means of theoretical analysis, simulations and a real implementation. Results show that the algorithm substantially outperforms previous approaches in terms of throughput and delay.

Vehicular communications will increase road safety, traffic efficiency and driving comfort, by enabling vehicles to form Vehicular Ad-hoc Networks (VANETs) and to directly exchange information. Additionally, connecting the VANET to an IP based network infrastructure (e.g., the Internet) may enhance those applications, and creating the opportunity for others such as infotainment ones (e.g., games, web browsing, e-mail, etc.). One of the functionalities needed to bring IP to vehicular networks is the capability of vehicles to autoconfigure an IPv6 address. GeoSAC is a mechanism enabling IPv6 address autoconfiguration in vehicular networks based on geographic routing. In GeoSAC, as a result of the mobility of the vehicles, they cannot always use the same IP address. Each new address configuration introduces a delay during which communications are interrupted. We propose an improvement for GeoSAC, based on the caching of Router Advertisements, to avoid this disruption time. We also analytically model the probability of achieving seamless IP address reconfiguration as well as an expression for the average configuration time of nodes. The model is validated through extensive simulation. Results in different realistic scenarios show that the use of our proposed optimisation is valuable and would improve the performance in terms of configuration time and/or signaling overhead and the average configuration time expression would provide network administrators with a powerful tool that can be used during the network design.

Mohamed Hefeeda is an assistant professor in the School of Computing Science, Simon Fraser University, Canada, where he leads the Network Systems Lab. He holds a Ph.D. from Purdue University, USA, and M.Sc. and B.Sc. from Mansoura University, Egypt. His research interests include multimedia networking over wired and wireless networks, peer-to-peer systems, network security, and wireless sensor networks.