The year 2020 has served up some unprecedented challenges for the human race in every aspect, with wireless connectivity more important than ever. Particularly as millions continue to work and learn remotely, our connected world of devices, vehicles, homes and cities is expanding exponentially. According to a report from GSMA and ABI Research, the number of mobile subscriptions worldwide had already reached 8.1 billion by 2017 at an annual growth rate of 5.4 percent. It’s now predicted that by 2025 the number will increase to 9.8 billion, with 3G and 4G representing 51 percent of total subscriptions and 91 percent of the total traffic generated, while 5G subscriptions are expected to exceed 849 million.
There’s no doubt that the fifth generation of connectivity will provide faster download speeds and more capacity than 3G and 4G networks when fully deployed. But until then, there are significant challenges to overcome, one of the most important of which is security. In addition to a larger attack surface as a result of the massive increase in connectivity and a greater number of devices accessing the network, new vulnerabilities have surfaced due in large part to the extension of security policies for new types of Internet of Things (IoT) devices, as well as the insufficiency of perimeter defenses. There’s also the fact that 5G networks will interoperate with legacy 3G and 4G networks, which rely on General Packet Radio Service GPRS Tunneling Protocol (GTP). According to a report from Positive Technologies, as long as GTP is in use, the protocol’s security issues will impact 5G networks.
Perhaps even more pressing for 5G is the need for the right technology to connect the network to the core. Particularly as the big three U.S. telecom providers — Verizon, AT&T and T-Mobile — roll out the first 5G networks in stages, mobile operators are seeking high-speed, high-capacity, low-latency backhaul solutions that can be rapidly and flexibly deployed wherever needed. While RF millimeter wave (mmWave) has become a preferred wireless technology for backhaul, offering high capacity, efficiency and throughput, there are fundamental issues. For instance, because of the limited reach of mmWave, arrays of antennas will be required, with no clear understanding of how many base stations and small cells will be necessary to provide adequate coverage in urban, suburban and remote regions. Even then, objects (buildings, tress, etc.) and weather can interfere with mmWave signals. Finally, RF is inherently less secure than fiber.
With the critical need to address and satisfy not only latency, data security and bandwidth limitation but also licensing, cost and last mile access issues, governments and telecom companies are exploring a range of options, including optical wireless communication (OWC). A license-free wireless technology NASA has been using for decades in its Laser Communications Relay Demonstration and the Orion Exploration Mission 2 Optical Communications project, OWC offers rapid point-to-point data transmission via beams of light that connect from one telescope to another using low-power, eye-safe, infrared lasers in the terahertz spectrum. Many military applications have also relied on OWC for decades to communicate securely over unknown terrain. Over the years, OWC has benefited from advancements in amplifiers, lasers and detectors, as well as commercial investment from the traditional defense and aerospace companies in the U.S., Japan and Europe.
While OWC is still relatively new in the commercial space, and thus not as prominent in the 5G discussion, it offers significant benefits over mmWave backhaul. In addition to delivering huge volumes of data at super-fast speeds — 20 to 50 Gigabits per user — OWC works in dense urban areas where spectrum is limited. More important, it offers built-in security. Here’s why:
- Precision - Because lasers are highly directional and more precise by nature, OWC has very low beam divergence, thus the chances for being intercepted by an unintended receiver is very low compared to traditional RF communications, which broadcasts signals to a large field of regard.
- Power efficiency - Since the individual photons of a laser beam have much more energy than the radio photon, and because OWC beams are so tightly focused, they require much less power than traditional RF to transmit signals yet deliver significantly higher throughputs. Very low power transmission also aids in the ability for OWC signals to remain “unseen” from potential threats of detection, thus increasing confidence in securing the wireless transmission.
- Encoded data – OWC offers an opportunity to encode data in polarization, quadrature amplitude modulation (QAM ) and wavelength-division multiplexing (WDM), as well as other methods. In certain systems such as Multimedia over Coax Alliance (MoCA), for example, outgoing beams are right-hand circular polarized (RHCP) while incoming beams are left-hand circular polarized. This allows for full bi-directional transmission of data. Adaptations to this architecture, however, could also allow for either higher data throughputs (double the data rate) or for the encoding of information (i.e. security keys) into the relationship between the beams to ensure the transmission stream has not been compromised.
With security a top concern for 5G operators, the future of 5G will arguably depend on the industry’s ability to collaborate to find solutions that augment RF and serve the last mile securely while fulfilling its promise to improve communication and connectivity on every level — for everyone.