5G Opens Up mmWave Spectrum: Which Frequencies Will Be Adopted?
While the ITU, 3GPP and other standards bodies decided on 2020 as the deadline for the 5G standard to be defined, cellular providers are working on an accelerated schedule for delivering 5G service. In the U.S., Verizon and AT&T plan to test an early version of 5G in 2017. Korea will conduct 5G trials at the 2018 Olympics, and Japan wants to demonstrate 5G technologies at the 2020 Tokyo Olympics. Through these varying groups and motivations, the following frequencies are emerging as the initial candidates for 5G: 28, 39 and 73 GHz.
These three frequency bands have emerged for several reasons. First, unlike 60 GHz, which has approximately 20 dB/km loss due to oxygen absorption, they have much lower oxygen absorption rates. This makes them more viable for long distance communications. These frequencies also function well in multipath environments and can be used for non-line-of-sight (NLoS) communications. By combining highly directional antennas with beam forming and beam tracking, mmWaves can provide a reliable and very secure link. Ted Rappaport and his students at NYU Polytechnic School of Engineering have already begun research on the channel properties and potential performance for 28, 39 and 73 GHz. They have published several papers with propagation measurements and studies on potential service outages at these frequencies. This data and research, combined with the availability of spectrum worldwide, make these three bands the starting point for mmWave prototyping.
