Joerg Widmer

Joerg Widmer is Research Professor and Research Director of IMDEA Networks in Madrid, Spain. Before, he held positions at DOCOMO Euro-Labs in Munich, Germany and EPFL, Switzerland. He was a visiting researcher at the International Computer Science Institute in Berkeley, USA, University College London, UK, and TU Darmstadt, Germany. His research focuses on wireless networks, ranging from extremely high frequency millimeter-wave communication and MAC layer design to mobile network architectures. Joerg Widmer authored more than 150 conference and journal papers and three IETF RFCs, and holds 13 patents. He was awarded an ERC consolidator grant, the Friedrich Wilhelm Bessel Research Award of the Alexander von Humboldt Foundation, a Mercator Fellowship of the German Research Foundation, a Spanish Ramon y Cajal grant, as well as nine best paper awards. He is an IEEE Fellow and Distinguished Member of the ACM.

Tutorial: “Practical Millimeter-Wave Networking”

Abstract: This tutorial will highlight several of the challenges of and possible approaches for networking in the millimeter-wave band. The high bandwidth available at millimeter-wave frequencies allows for very high data rates, and the latest wireless technologies are already starting to exploit this part of the radio spectrum to achieve rates of several GBit/s per user. Communication at these frequencies typically uses directional antennas, which brings about interesting challenges to align antenna beams. Given the high penetration loss, most obstacles (for example a person) also completely block the signal. On the one hand side, this results in much less interference compared to omni-directional communication at lower frequencies, allowing for a high degree of spatial reuse and potentially simpler Medium Access Control Protocols (MAC) and interference management mechanisms. On the other hand, high directionality may cause deafness due to beam misalignment, and links may appear and disappear over very short time intervals. This causes sudden interruptions to the communication that can last milliseconds to seconds, in particular for mobile devices. Designing efficient yet resilient millimeter-wave network architectures is therefore quite challenging. The tutorial mainly focuses on networking aspects of the MAC layer and above. It starts by an overview of mm-wave communication characteristics, and then delves into the most important network and protocol design aspects, ranging from beam-training and medium access control to transport protocol design. Given the difficulty of millimeter-wave experimentation, the tutorial further covers suitable testbed platforms that can be used for practical millimeter-wave research.

Keynote: “Millimeter-Wave Localization and Location-Based Network Management“

Abstract: Millimeter-wave communications have emerged as one of the most promising options to vastly increase wireless data rates due to the high bandwidth they offer. Given the high path loss at millimeter-wave frequencies, such systems require directional antennas to achieve a good communication range. The systems’ large bandwidth allows for very accurate ranging, and the phased antenna arrays can be used to derive precise angle information. This keynote will discuss approaches for low-overhead active and passive millimeter-wave location systems, as well as simultaneous localization and mapping.

Efficient and reliable operation of millimeter-wave networks in dynamic environments is very challenging due to the requirement to continuously align the beam directions of the devices’ antennas. Due to the high penetration loss, the paths between the antennas also need to be free of blocking obstacles. We show how location information can be used to scale millimeter-wave networks to high-density deployments, to rapidly adapt to dynamic and mobile environments, and to consistently achieve high data rates. By estimating device locations and learning the environment, it is possible to speed up beam training, optimize access point association, and predict (and counteract) future blockage by finding alternate propagation paths. Such mechanisms then turn a collection of very-high-speed but brittle millimeter-wave links into an efficient, low-latency, and reliable network.