Christopher M. Collins, PhD, is a Professor of Radiology at the School of Medicine of the New York University, where he also serves as the departmental Director of Research Faculty Affairs and Chair of the Departmental Appointments and Promotions Committee. He is an expert on the simulation, measurement and evaluation of the effects of nonionizing radiation in the human body, especially in Magnetic Resonance Imaging (MRI), and has also published work on the safety evaluation of 5G technology. He has published well over 80 peer-reviewed works and nearly 300 meeting abstracts on these and related topics. He has given numerous invited talks and lectures on these topics. His work is largely funded by the US National Institutes for Health. He is a Senior Member of the IEEE and has served in a wide range of elected offices and appointed roles for the International Society for Magnetic Resonance in Medicine (ISMRM).
Tutorial: Progress and Perspectives on 5G at NYU Wireless
Abstract: Wireless data trafﬁc has been increasing at a rate of over 50% per year per subscriber, and this trend is expected to accelerate over the next decade with the continual use of video and the rise of the Internet-of-Things (IoT). To address this demand, the wireless industry is moving to its ﬁfth generation (5G) of cellular technology that will use millimeter wave (mmWave) frequencies to offer unprecedented spectrum and multi-Gigabit-per second (Gbps) data rates to a mobile device. Mobile devices, such as cell phones, are typically referred to as user equipment (UE). A simple analysis illustrated that 1 GHz wide channels at 28 or 73 GHz could offer several Gbps of data rate to UE with modest phased array antennas at the mobile handset, and early work showed 15 Gbps peak rates are possible with 4×4 phased arrays antenna at the UE and 200 m spacing between base stations (BSs). 5G mmWave wireless channel bandwidths will be more than ten times greater than today’s 4G Long-Term Evolution (LTE) 20 MHz cellular channels. Since the wavelengths shrink by an order of magnitude at mmWave when compared to today’s 4G microwave frequencies, diffraction and material penetration will incur greater attenuation, thus elevating the importance of line-of-sight (LOS) propagation, reﬂection, and scattering. Accurate propagation models are vital for the design of new mmWave signaling protocols (e.g., air interfaces). Over the past few years, measurements and models for a vast array of scenarios have been presented by many companies and research groups. Here we will summarize key 5G system concepts of emerging mmWave wireless communication networks and present 5G propagation challenges and antenna technologies, then give discuss recent mmWave channel models developed by various groups and standard bodies, and discuss requirements for successful implementation of 5G communications networks, such as employing steerable directional antennas at base stations and mobile devices.
- Rappaport TS, Sun S, Mayzus R, Zhao H, Azar Y, Wang K, Wong GN, Schulz JK, Samimi M, Gutierrez Jr F. Millimeter wave mobile communications for 5G cellular: It will work!. IEEE access. 2013 May 10;1(1):335-49.
- Rappaport TS, Xing Y, MacCartney Jr GR, Molisch AF, Mellios E, Zhang J. Overview of millimeter wave communications for fifth-generation (5G) wireless networks-with a focus on propagation models. arXiv preprint arXiv:1708.02557. 2017 Jul 24.
Keynote: Ensuring Radiation Safety in the mmWave Regime – New Challenges for a New Generation
Abstract: With the increasing demand for higher data rates and more reliable service capabilities for wireless devices, wireless service providers are facing an unprecedented challenge to overcome a global bandwidth shortage. Early global activities on fifth-generation (5G) wireless communication systems suggest that millimeter-wave (mmWave) frequencies are very promising for future wireless communication networks due to the massive amount of raw bandwidth and potential multigigabit-per-second (Gb/s) data rates. Both industry and academia have begun the exploration of the untapped mmWave frequency spectrum for future broadband mobile communication networks. But moving to higher carrier frequencies presents interesting, somewhat paradoxical challenges in assessing the safety of wireless communication devices. On the one hand, the energy does not penetrate as deeply into the tissues so exposure of internal organs should be less of an issue. Also, the skin, which absorbs an increasing majority of the energy as frequency increases, is fairly resilient to heating. But on the other hand, because an increasing portion of the energy is absorbed in a smaller portion of the tissue, the skin might be expected to be heated more readily than at lower frequencies if similar radiation power is used. Also, the accurate measurement of absorption in a very small region becomes more difficult and the current parameters used for evaluating exposure at frequencies above 6GHz become less relevant to safety, as they refer only to the power density of energy in open space rather than that within tissues. Here we will review regulatory guidelines, power absorption distributions, temperature distributions, and assessment methods functions of the frequency of incident energy and discuss ways to meaningfully assess radiation safety for 5G and beyond.