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Radiowave Propagation
Published in Indrakshi Dey, Propagation Modeling for Wireless Communications, 2022
HF band (3–30 MHz) is used in Ionospheric long haul hops for radio broadcasting services, aeronautical and maritime mobile communications. VHF Band (30–300 MHz) is used in long distance receiving for audio and video broadcasting, aeronautical and maritime radio communications, over-horizon radio communication by tropo-scatters, radar and radio navigation services, analog cordless telephone, radio paging services and lower earth orbit (LEO) satellite systems, while UHF band (300–3,000 MHz) is used for TV broadcasting, cellular mobile radio services, mobile satellite, GPS, astronomy communications, radar and radio navigation services. SHF band (3–30 GHz) is used for radar systems and military applications, TV satellite broadcasting and remote sensing from satellites. EHF band (30–300 GHz) is being planned for broadband-fixed wireless access, future satellite and high-altitude platform applications. Similarly, micro-metric and nano-metric bands are being planned for space radio communications, satellite communications, laser and infrared radio communications, and fiber optics cable networks.
Wireless Communication
Published in Dave Birtalan, William Nunley, Optoelectronics, 2018
RF frequencies range from the extremely low frequency (ELF) of 3 Hz to the ultrahigh frequency band (UHF) 300 to 3,000 MHz. Some typical RF wireless applications include cellular telecommunication, radio and television broadcasting, data networks, remote controls, and police and fire department radio communications. Microwave electromagnetic radiation ranges from 1 GHz, as recognized by the IEC and IEEE, up to the extremely high-frequency (EHF) range of 300 GHz. Microwaves are also used in telecommunications for point-to-point communications, for ground-stations-to-orbiting-satellites telecommunication applications, and wireless LAN protocols such as 802.11 (2.4 GHz). Radar, in a noncommunication application, utilizes microwave radiation to identify the range, speed, and characteristics of distant objects. Some of the wireless standards available are IEEE 802.15.1 (Bluetooth—2.4 GHz and 2.5 GHz, version 1.2), IEEE 802.15.4 (Zigbee—2.4 GHz), and IEEE 802.11a/b/g (WiFi—2.4 GHz b/g and 5 GHz/a).
Transport Network
Published in Saad Z. Asif, 5G Mobile Communications Concepts and Technologies, 2018
The microwave radios that operate in the above mentioned frequency band can be used to address the backhaul needs of 5G. This frequency spectrum is part of the millimeter band that starts at 30 GHz and ends at 300 GHz (ITU EHF [Extremely High Frequency]) and where the corresponding free space wavelengths range from 10 to 1 mm. The research on millimeter wave technology started in the 1890's and a lot of work was done through World War II [9]. The very famous curves showing average atmospheric absorption of millimeter waves were published by Rosenblum in 1961 [10]. These curves, as shown in Figure 10.4, have doubtlessly been used in scores of articles, reports, and books since their inception.
Design and development of T-Shaped antenna structure for wireless communication
Published in Waves in Random and Complex Media, 2022
A massive heterogeneous network of various devices will be linked to each other over the internet, requiring a communication network capable of handling such a large number of devices. The internet of things (IoT) is a new technology that connects and communicates a huge number of sensors, appliances, and gadgets. A possible unlicensed frequency range at 17 GHz is also being investigated for IoT applications, resulting in a high-bandwidth wireless local area network. Millimeter-wave is a spectrum of frequencies between microwaves and infrared (IR) waves and is often referred to as extremely high frequencies (EHF), making it ideal for 5G networks. They enable frequencies ranging from 30 to 300 GHz to be transmitted. The wavelength ranges from 1 to 10 millimeters. More spectrums may be occupied using millimeter-wave. Wireless data rates in the microwave and lower frequency ranges are about 1 gigabit per second [11–15].
Reviewing the Scope of THz Communication and a Technology Roadmap for Implementation
Published in IETE Technical Review, 2021
Md Hafizur Rahaman, Aparajita Bandyopadhyay, Surendra Pal, Kamla P. Ray
The bands, represented as EHF (Extremely High Frequency) and THF (Tremendously High Frequency) in Figure 1, offers a total available bandwidth over hundreds of GHz. The new 5G technology will essentially use the lower frequency part of EHF while the higher frequency part of EHF and the band spectrum of THF are under active scrutiny in relation to their technological feasibility in commercial communication sector. Several contemporary surveys chronicle these research efforts [3–5], and experimental realization in these bands is also being reported recently [6–8]. These bands (0.1–3 THz) in EM spectrum are in the Terahertz (THz) range which spans across the range between microwave and far-IR “bridging the gap” between the “electronics” and “photonics”, respectively. Consequently, THz range enjoys some hallmark characteristics of both electronics and photonics world and offers some unique set of features and poses some fundamental challenges.