THz and Photonic Seamless Communications

Terahertz (THz) wave can offer over 100-Gb/s wireless transmission by the use of wide spectrum. Due to features of high-frequency waves such as lightwaves, THz can have high directivity. To mitigate congestion of radio spectrum, advanced modulation formats will play significant roles in THz bands as well as in conventional millimeter-wave or microwave hands. This paper will provide overviews on spectral efficiency and transmission capacity of THz wave systems. Power consumption of radio links would be also an important issue to reduce OPEX of networks. Survey on power consumption of short-distance wireless systems implies that high-speed radio transmission using THz bands would provide low power consumption transmission. However, THz transmission distance will be limited in shorter than a few kilometers due to attenuation in the air. Seamless networks consisting of THz links and optical fibers would provide high-speed, low-latency, and low power consumption data transmission. Devices and signal processing functions developed for optical fiber transmission can be applied to high-speed THz communications.