Investigation on millimeter-wave spectrum for 5G

Mobile traffic is increasing exponentially year by year and it will be over 1000 times higher than that of today in the near future. In order to tackle this matter, millimeter wave mobile access networks which can provide several GHz bandwidth attract international attention. This paper investigates the candidates of millimeter wave spectrum for 5G by referring to several ongoing 5G R&D projects and considering the spectrum allocation status of Japan, US, and EU. Consequently, five candidates are selected, (1) 31.8GHz-33.4GHz, (2) 45.5GHz-47.0GHz, (3) 47.2GHz-50.2GHz, (4) 55.78GHz-76.9GHz, and (5) 81.0GHz-86.0GHz. Additionally, for the evaluation of each band we develop path loss models for each candidate band by using an interpolation technique. Moreover, we compare the performance of the heterogeneous network (HetNet) system assuming new spectrum usage in terms of system rate and reveal that the system which has larger bandwidth can achieve the higher system rate regardless of large pathloss value, especially in high traffic case. This result shows that the system which can have large bandwidth will have the high priority for the future mobile wireless networks.