The frequency range between 57 GHz and 64 GHz, known as the 60 GHz band, has been cleared by the Federal Communications Commission( FCC) for license-free use for gigabit WLANs and other wireless technologies. Part of this frequency range is part of the ISM band.
Certain limits must be observed when using license-free frequency bands. The guidelines issued by the Federal Communications Commission (FCC) for the use of the 60 GHz band stipulate a maximum transmission power( EIRP) of 40 dBm in most countries. For point-to-point transmissions, it is +55 dBm and a minimum antenna gain of +30 dBi. Since the free- space attenuation at 60 GHz is 88 dB at a distance of ten meters, the received field strength at a distance of ten meters is -48 dBm. The range of 60 GHz technology is therefore relatively short. The 60 GHz waves, whose wavelength is 5 mm, cannot penetrate walls or tree trunks. Propagation is only possible via line-of-sight( LOS) links and is also highly weather-dependent. Multipath propagation with small propagation time differences causes wave shifts that have a strong negative impact on reception quality. 60 GHz technology can therefore only be used indoors or outdoors over short distances.
In the European allocation table of the ITU Radio Regulations, the entire 60 GHz band is divided into the frequency range between 57 GHz and 62 GHz, and further into the ranges between 62 GHz and 64 GHz and 64 GHz to 66 GHz. All ranges are used for the fixed service. The frequency band from 57 GHz to 59.3 GHz is allocated to the Earth Exploration Satellite Service (EESS) and the frequency range between 58.2 GHz and 59 GHz for radio astronomical observations.
- An initiative of well-known consumer electronics companies, the WirelessHD Alliance,(WiHD), has already established WirelessHD, a standard that supports the 60 GHz frequency range for wireless transmission of audio and television signals between receiving equipment and the television display. WirelessHD envisions data rates of 10 Gbps and is suitable for transmission of uncompressed HDTV.
- IEEE is targeting the same application and is working on a wireless High Definition Multimedia Interface( HDMI), Wireless HDMI(WHDMI), with a data rate of 5 Gbps. Such an interface will allow a DVD drive to wirelessly transmit uncompressed video to the flat panel display. IEEE is also working on a gigabit WLAN with data rates of several gigabits per second, operating in the 60 GHz band, in the 802.11ad, 802.11ay and 802.15.3.c working groups. Peripheral devices can be connected and mass data transferred via such a high-speed WLAN.
- There is also a wireless access technology in the 60 GHz range for broadband connection of homes to the Internet: Wireless to the Home(WTTH).
- The WiGig Alliance has brought microwave technology in the 60 GHz band to the Wireless DisplayPort( wDP). This wireless technology operates in a 7 GHz wide frequency band and achieves data rates of 7 Gbps.
- The European Telecommunications Standards Institute( ETSI) has also included the 60 GHz band in its plans and is specifying a Multiple Gigabit Wireless System( MGWS) for home applications. The German Federal Network Agency 's (BNetzA) Frequency Utilization Plan(FreqNP) designates the 60 GHz band for space exploration radio, earth exploration radio, directional radio and inter- satellite links.
- The FCC has proposed the microwave band as a key technology for LTE backhauls, for densely populated areas where experience shows that the 4th generation of mobile communications( 4G) will always require additional frequency bands for further mobile services.