Even if support for ever-faster mobile internet is the objective of each mobile next-generation network--including 5G and succeeding platforms--there is reason to believe that fixed wireless might be a growing use case.
The reason has to do with radio frequency signal propagation in the millimeter regions that will become necessary.
“Wireless channels in this frequency range experience large propagation and reflection loss, sporadic availability of line-of-sight links due to blockage, and molecular absorption,” notes MediaTek. “These phenomena result in a link performance with shorter range and an intermittent on/off behavior.”
Millimeter wave radio signals will use beamforming to overcome signal loss. But that also means near line-of-sight performance.
For that reason, sub-THz spectrum will be suited for fixed backhaul or nomadic devices communicating with a hub or as part of a network mesh, says MediaTek. The mesh capability is important as mobile users might move often among radio sites, requiring ability to shift between different radio sites on a dynamic basis.
In principle, this mesh approach means a mobile user might be serially (or simultaneously) connecting to different mostly line-of-sight radios. Though the physical paths might be fixed, the mobile user will take advantage of any number of fixed paths to sustain a mobile connection to the “capacity” millimeter wave spectrum, while defaulting to coverage spectrum when necessary.
Faster speeds are coming. The issue is how the radio access network is re-architected to take advantage of frequencies that largely are line of sight.
MediaTek believes 6G will bring speeds 10 times to 100 times faster than 5G. That is not an unusual prediction. Indeed, every mobile digital generation has increased bandwidth by 10 times to 100 times, and reduced latency about 10 times, each generation.
Devices might also have the ability to sidelink, much as current devices can use Bluetooth for short-range device-to-device communications.
Other changes are possible. “A distributed MIMO deployment, where Tx-Rx signal pairs are not just bound to one node/site but distributed across multiple sites and nodes, has the ability to improve spectral efficiency and user experience across an area,” MediaTek says. That would not eliminate the use of transmitting “cells,” as the architecture is described as “cell free,” but rather mean user devices could communicate with more than one radio site at a time.
There would still be transmission cells, but user devices would be free to connect with any adjacent cells and not be restricted to a single tower or radio. The practical advantage for end users is that the edges of a cell would no longer be a transmission quality issue.
With a traditional one-cell connection design, lower signal strength at cell extremities has always meant reduced signal quality. In the cell-free design, signal quality close to the radio would be the same as quality at the edge of any single radio’s coverage. That includes the degree of packet loss.
The ability to incorporate non-terrestrial (satellite) connections with mobile connections also is envisioned. Artificial intelligence should be a native capability.
In the spectrum area, frequencies in the 7 GHz to 24 GHz bands will probably be parts of the 6G standard, as will spectrum sharing, MediaTek says.
No comments:
Post a Comment