5G: The Future is Now
The current 4G standard uses frequencies below 6 GHz, but 5G will use frequencies in the 30 GHz to 300 GHz range. 5G will initially be around 60GHz or 10x the frequency of 4G.
This has several advantages from the physics perspective:
The higher the frequency of a signal the shorter the wavelength (think of the size of a tweeter vs the size of the woofer in a stereo, or the size of a piccolo vs the the size of a tuba) so things like antennas can be much smaller. The same goes for the size of the components in the amplifier stages of a transmitter. The size of the components in the transmitter and antenna is one of the limiting factors in cell phone handsets in 3/4G phones for example.
The limiting factors in things like mobile devices are generalized into a parameter called SWaP; Size, weight and Power.
It so happens it is more efficient to make RF power at these higher frequencies as the size of the transistors are proportionally smaller.
So if you can put a more efficient transmitter and smaller antenna inside a a mobile device, or a cell phone handset you might be able to put a larger battery in it for example.
Also since the wavelength is much shorter it takes less time to send a given number of bits, so the data rate can be made much higher (1G bits per second vs 10G+ bits per second with 5G). Also things like data latency (delay) can be reduced.
Because signals such as voice and data are multiplexed (effectively chopping up and combining several signals and sending them on one channel and reconstructing them into separate signals the receiving end) you can pack more bits into a given size channel. Each channel takes up a narrow slice of the available spectrum.
For mobile communications there is also a limit on how fast the handset (transmitter) can be moving with respect to the tower (receiver). This is due to the Doppler shift; if you move too fast, the data from one channel will appear in an adjacent channel / slice of the spectrum (think of the sound of a train or jet as it approach’s you). The higher the radios frequency the less the speed effects this (because the radio’s frequency is significantly higher than the Doppler shift frequency). This will allow cell phones technology to work at commercial airliner or supersonic speeds soon for example.
From a revenue perspective, a 4G cell phone can support on average something like 1000 channels over a 1km area, whereas 5G can support 1,000,000 channels over the same 1km area, so more customers per cell, or perhaps more correctly fewer towers per customers in a given area.
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Written by Alexander Fleiss & Edited by Rachel Weissman