For many of us, when we send a text or make a call from a cellphone, we're relying on 4G. However, as much as we rely on it, few of us know what it actually means.
In reality, the “G” in these terms only stands for the generation of wireless mobile telecommunications technology. 2G brought voice communication, 3G gave access to the web and some video services, and 4G made things such as the app economy possible. But with the applications of our wireless technology expanding at such a rapid rate—from smartphones and tablets to fueling the Internet of Things–4G is no longer going to cut it.
“5G opens the door to a more connected society with high data rates, low latency, and massively interconnected devices,” says Carnegie Mellon University Engineering and Public Policy Department Head Doug Sicker. “This jump in connectedness comes at a high network cost, so a great deal of thought is being put into increasing capacity while minimizing cost.”
Although the rest of the world is calling 5G the next big thing, Sicker and his collaborators—Kazi Mohammed Saidul Huq of the Instituto de Telecomunicações in Portugal and EPP CMU graduate student Rohit Singh—are looking beyond 5G. Their project aims to take 5G networks into higher terahertz speeds and lay the groundwork for future networks.
“Portugal has invested substantially over the last decade in advancing their science and technology production,” Sicker says, “And next-generation communications are a part of this, along with a push on AI and biotech. Our work will provide new spectrum for IoT-type services, particularly those with bandwidth-intense demands.”
Sicker’s work in Portugal is focused on the growth of IoT networks for indoor use. Current 3G and 4G technologies penetrate walls and vehicles, which is useful for reaching phones inside buildings and cars. However, the 3G/4G spectrum can only support a limited number of users at high data rates. 5G networks running at THz (tremendously high frequency) speeds support a much higher number of users at much higher data rates. Unlike earlier networks, however, these ultra-fast frequencies cannot penetrate walls.
When a signal cannot move through walls, it becomes trapped within a limited area. While this may sound like a disadvantage, containing the signal in a small space like a building (or even a room) lets several users and devices reuse the same spectrum. Furthermore, this containment keeps harmful interference to a minimum, letting the same frequency be used from one house to the next without getting in each other’s way.
So, although 4G may work fine for cellphones and streaming services, a 5G Advanced opens new possibilities for connected indoor devices: smart thermostats and refrigerators, security systems, and even sensors to monitor building health. Although THz frequencies deliver lots of bandwidth, which can cater to densely data-savvy devices, it opens new realms of technical and policy-related challenges. The aim of this project is to overcome the inherent challenges with the THz band.
