Wi-Fi and 5G 143
bands, and therefore able to adapt to the environment. The peak data
rate is 7 Gbps. The range in the 60 GHz band is less than 10 meters, so
this network is said to belong to the category of PANs (Personal Area
Networks).
The channels used in the base mode correspond to 57.24 GHz,
59.4 GHz, 61.56 GHz and 63.72 GHz. The bandwidth is 2.16 GHz.
To compensate for the significant attenuation of the signal, IEEE
802.11ad requires directional antennas which can focus the radio
beam within a 6° angle. With this very narrow beam, the IEEE
802.11ad standard is used outdoors between directional antennas with
a direct view, or indoors but counting on ricochets to reach the
addressee. Indeed, with a 6-degree beam, the connection between two
machines is often complex. Fortunately, there is an option which
enables us to direct the beam so that the two machines wishing to
connect can communicate with one another.
Two applications of IEEE 802.11ad are mentioned in the standard.
The first corresponds to wireless connections for peripheral
computers, with the aim of doing away with the numerous cables
which trail everywhere. This application also facilitates simple sharing
of peripheral devices. The second application relates to consumer
electronics, associated with wireless technology, such as stereo
equipment, HD televisions, and online gaming systems.
6.5. IEEE 802.11af
The IEEE 802.11af technique pertains to a totally different method
to increase the data rate: the use of cognitive radio. It consists of
reusing frequency bands which are not being used at a time t in the
television bands.
More generally, recent measurements show that, in spite of their
scarcity and their high price, frequencies between 0 and 20 GHz are
under-used – often less than 10%.
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bands, and therefore able to adapt to the environment. The peak data
rate is 7 Gbps. The range in the 60 GHz band is less than 10 meters, so
this network is said to belong to the category of PANs (Personal Area
Networks).
The channels used in the base mode correspond to 57.24 GHz,
59.4 GHz, 61.56 GHz and 63.72 GHz. The bandwidth is 2.16 GHz.
To compensate for the significant attenuation of the signal, IEEE
802.11ad requires directional antennas which can focus the radio
beam within a 6° angle. With this very narrow beam, the IEEE
802.11ad standard is used outdoors between directional antennas with
a direct view, or indoors but counting on ricochets to reach the
addressee. Indeed, with a 6-degree beam, the connection between two
machines is often complex. Fortunately, there is an option which
enables us to direct the beam so that the two machines wishing to
connect can communicate with one another.
Two applications of IEEE 802.11ad are mentioned in the standard.
The first corresponds to wireless connections for peripheral
computers, with the aim of doing away with the numerous cables
which trail everywhere. This application also facilitates simple sharing
of peripheral devices. The second application relates to consumer
electronics, associated with wireless technology, such as stereo
equipment, HD televisions, and online gaming systems.
6.5. IEEE 802.11af
The IEEE 802.11af technique pertains to a totally different method
to increase the data rate: the use of cognitive radio. It consists of
reusing frequency bands which are not being used at a time t in the
television bands.
More generally, recent measurements show that, in spite of their
scarcity and their high price, frequencies between 0 and 20 GHz are
under-used – often less than 10%.
www.it-ebooks.info