Post-doc Advisor at King's College London (Aug. 2010 - Dec. 2011)

"My collaboration with David started when he joined my EPSRC First Grant project as a postdoctoral research associate at King’s College London in 2010 and has continued to the present day. The greatest strength of David lies in his strong sense of responsibility and leadership as an independent researcher. He is dedicated to staying up-to-date with the latest advancements in his field and continuously refining his research skills. I am particularly impressed by his "can-do" attitude - his positive mindset and proactive problem-solving approach - without which many of our achievements during the EPSRC project, including the book “Heterogeneous cellular networks: theory, simulation and deployment” published by Cambridge University Press in 2013, wouldn’t be possible. David has established himself as a highly regarded researcher. He has, in relatively short order, amassed an impressive publication track-record that stands comparison with any of his peers across the sector. In the meanwhile, he has provided considerate support, guidance, and mentorship to junior researchers and graduate students, both within his team and beyond. I am confident that David will continue to nurture a collaborative and supportive environment for young researchers, and I look forward to our ongoing partnership."

Prof. Xiaoli Chu - Department of Electronic and Electrical Engineering at University of Sheffiled


Advisor at DOCOMO Innovations (May 2011 - Sep. 2011)

"I mentored David at DOCOMO Innovations, Palo Alto, CA, between May-September, 2011, where he was a visiting postdoctoral researcher in leave from Kings College London. He worked on mobility and interference management for small cell networks. He was one of the most focused, productive, and easy-to-collaborate-with researchers that I have ever worked. He would come up with innovative approaches and new angles to tackle a challenging research problem, simulate and/or analyze the approach in practical conditions (he had a very good handle on ray tracing simulations and 3GPP specifications at that time which were difficult to come by), and always come up with interesting and insightful results. We had several highly cited papers published from the work he carried out during his visit, but the one that I liked the most was "On the expanded region of picocells in heterogeneous networks" which got published at IEEE JSTSP in 2012 which shows both the depth and breadth of David's technical skills right after finishing his PhD. I learned a lot myself from David,  both technically and attitude-wise, and I would not hesitate to do a PhD with him in grad school."

Prof. Ismail Guvenc - Department of Electrical and Computer Engineering at North Carolina State University

PhD student at Nokia Bell Labs (2013-2016)

"David's support and openness during my PhD fostered a nurturing environment where I felt empowered to explore and develop my ideas. Our collaboration resulted in notable successes, including published works and impactful contributions to the field of wireless communications. I deeply admire David's passion for research and his dedication to cultivating independent thinking. While our discussions sometimes posed challenges, they ultimately helped me to look at things from different angles and changed my perspective, fostering a more well-rounded approach to problem-solving and innovation. The lessons I learned from David continue to shape my career at Microsoft. His guidance equipped me with invaluable skills and insights that have been crucial to my professional growth. I take pride in the fact that my current role at Microsoft reflects the quality of mentorship I received from David. Thank you, David, for your unwavering support and inspiration."

Dr. Amir H Jafari - Senior AI Engineer, Microsoft

PhD student at Nokia Bell Labs (2019-2020) Collegue at Huawei Technologies (2020-2023)

"I first met David in 2016, right at the start of my PhD journey in Barcelona. I had just moved there, excited to explore new research topics and adapt to life in a new country. A few months before, I had received a Marie Sklodowska-Curie Fellowship to pursue my PhD in a European doctoral network.

At that time David was a researcher in Bell Labs and he came to Barcelona to speak about small cells and ultra-dense networks – a research area he mastered and significantly helped to advance. His presentation was so clear and well-organized, it really stood out from what I was used to seeing. Over the next few months, I even started using his slides as a model for my own. Also, it was inspiring to see someone apply fundamental research in the industry —it seemed like the perfect way to make a tangible impact.

That presentation made a lasting impression on me. So much so, that a couple of years later, I suggested to my PhD supervisor that we invite David to consider me for an internship at Bell Labs. The administrative gears turned slowly, but by February 2019, I found myself in Dublin, greeted by a chilly, snowy day. The thrill of entering Bell Labs was something else—I was especially struck by the display of the replica of the nine Nobel Prizes won by Bell Labs’s researchers (they became 10 meanwhile), a testament to its rich history.

My first technical meeting with David after joining Bell Labs is etched in my memory. I was explaining my work on optimization of network resources and he started quizzing me about the assumptions in my simulations. I was stumped—I had inherited the simulation code from previous PhD students and I was building on top of that work without questioning too much the foundations. At the end of that terrible meeting David reassured me saying  “I’ve seen worse,” which I didn’t take very positively at that time but taught me an invaluable lesson: to truly own and understand every aspect of my work, even parts handed down by others.

The following months at Bell Labs were truly amazing. It was easy to chat with researchers from different teams, especially during coffee breaks and lunches, which often turned into lively discussions about a wide range of topics. Those discussions were some of the most engaging I’ve ever had.

During the same period, I learned from David how things work in practice, both in real products and as defined in standards (that he knows very well), which was crucial for my work. I remember he once told me that most questions could be answered by referring back to Shannon’s capacity theorem. At first, this seemed like a bit of an exaggeration, but over time, it proved to be incredibly accurate.

One of the challenges we tackled together during my time at Bell Labs involved applying reinforcement learning to my research problem. It proved more complex than I initially thought. Our discussions, often intense, helped transform my initial frustration into fresh, testable ideas. After a few months of extensive tests, I managed to get some good results and this led to our first co-authored paper. Since then, we have written numerous papers together, making him my most frequent co-author.

Leaving Bell Labs on a sunny day in August was bittersweet—I hoped to return someday.

Fast forward a few months, I defended my PhD and was soon working at Huawei in Paris, with David as the technical leader of my team —a scenario that neither of us could have foreseen less than a year earlier. His leadership brought a sense of stability in our team and his deep expertise was our go-to resource. I remember our first task together was writing a very comprehensive paper surveying the literature on the energy efficiency of mobile networks, which required lot of time and effort but turned out to be very rewarding.

Later, we dove into modeling and optimizing mobile networks by using massive data collected by real networks, and machine learning. This project was very challenging. During one of our regular meetings, I suggested applying machine learning to model the power consumption of mobile base stations. This idea evolved into a major research endeavor that occupied me for a couple of years, culminating in the development of an algorithm that was integrated into the final product, now deployed globally, which I consider one of my greatest results. Throughout this period, in the most difficult moments, David taught me the ins and outs of managing projects under pressure—a skill just as crucial as technical expertise, which significantly shaped my approach to work.

Reflecting on all these experiences, I feel incredibly fortunate to have been mentored by David during the crucial early years of my career. He imparted much more than technical knowledge; I learned from him how to present my work effectively, and handle challenging situations that are always under the corner in our daily job. Beyond these skills, he instilled in me the importance of being proactive and the ability to think creatively and push boundaries.

Currently I’m still working in Huawei as a senior researcher, and I believe that much of my success in this role owes a lot to those days of intense discussions and shared discoveries."

Dr. Nicola Piovesan - Senior Engineer, Huawei Technologies