Research stay at Rice University 2018-19

During my research stay (from November 2018 to February 2019) at Rice University, I have been working with the Networks research group (RNG), lead by Prof. Edward Knightly. The people on RNG is amazing: really focused on research, with hard-working ethics, honest and so welcoming with visitors. 

Apart from the seminars and other intra-group activities (e.g., running experiments with the drones of the ASTRO project), I have also participated in the weekly Wireless Research Department meetings, where interesting edge state-of-the-art topics like THz wireless communication, 5G (and 6G!) novelties, or even beamforming for audio signals were discussed.

As for the main contribution of the stay, I have been working on the design and development of a custom spectrum analyzer built with WARP programmable wireless platforms. The key and novel feature of the system is the ability to sniff the full IEEE 802.11ac/ax 5 GHz band in a real-time manner. Preliminary experiments on the field have been also conducted. The dataset gathered from these experiments is expected to be published as a valuable asset for the research community and, especially, for the advancement of my thesis in the analysis of multi-channel access techniques.

At the beautiful Duncan Hall building in Rice University campus (Houston, Texas - Feb. 2019)


PhD's main topic

Enhancing Wireless Networks Performance through Learning-based Dynamic Channel Bonding and Dynamic Spectrum Access.

The number of hungry-bandwidth devices accessing the Internet through Wireless Local Area Networks (WLANs) Access Points (APs) such as laptops, smartphones, and tablets, is increasing drastically at the same time that users' bandwidth requirements do. Nonetheless, as WLANs operate in the industrial, scientific and medical (ISM) radio bands, even coexisting in dense scenarios (e.g. home departments), they are usually managed autonomously by different operators, which prevents applying centralized interference management techniques such as spectrum allocation.
By means of channel bonding (CB), a technique whereby nodes (i.e., devices and APs) are allowed to use contiguous sets of available channels for transmitting, higher throughputs are potentially achieved. However, due to the use of wider channels increases the contention among nodes, undesirable lower performances may be experienced in overlapping networks.
To mitigate such a negative effect, dynamic channel bonding (DCB) techniques are used to select the channels based on the instantaneous spectrum occupancy. Nonetheless, their dynamics and impact on networks performance is still not well known. Preliminary studies modeling WLAN scenarios as Continuous Time Markov Chains (CTMNs) reveal interesting particularities when implementing DCB, such as the fact that selecting always the maximum number of available channels may cause throughput losses in the long-term. 
In this first stage of the PhD we aim to deeply characterize channel selection effects, and to propose and validate learning-based policies for enhancing WLANs performance through efficient DCB and dynamic spectrum allocation in order to make networks operate close to their optimal throughput even in highly variable scenarios.

Other projects

I am also involved in other research projects in the fields of the Internet of Things (IoT), Low Power Wide Area Networks (LPWANs), and WLAN management.

Testing traps (STAs) in an olive tree orchard (Falset, Tarragona - April 2017)