In order to meet enormous demand for capacity, 6G will expand into new bands of radio spectrum and provide new means of reusing spectrum through extreme massive MIMO.
Today, the amount of knowledge in the world is doubling every 12 hours, and the real-time data from which new knowledge is extracted is growing even faster. All that data and knowledge is being transmitted through communication networks. Future applications like immersive digital world experiences, 3D digital twinning and fiber-like fixed wireless will demand considerable bandwidth.
As a consequence, demands on our networks have grown and will continue to grow astronomically, leading to massive demands for new capacity. To offer some perspective, a 35% year-over-year increase in demand would necessitate a 2000% increase in capacity over 10 years. Hence 6G must be designed to provide, at minimum, 20 times more wide-area capacity than 5G.
To reach 20X, 6G must tap new sources of spectrum that will provide both coverage and high data rates. 6G must also use its new and existing assets more efficiently with advanced antenna-array technologies.
6G should support spectral bandwidths on the order of 400 MHz in new mid-bands and several GHz in new high bands, greatly increasing the baseline capacity of a single cell. But in order to reach those bandwidths, regulators will need to open up new sources of spectrum. New, low-frequency bands will give signals tremendous reach, making them ideal for rural areas. Sub-THz bands beyond 90 GHz could supply extremely high data rates for bandwidth-intensive applications, as well as connect sensing networks. Finally, as new ‘mid-band’ spectrum between 7 GHz and 20 GHz opens up for 6G, we’ll see the best of both worlds – extreme capacity and great coverage.
6G will see the spectral efficiency of wide area cells improve substantially through the application of more sophisticated multiple-input multiple output (MIMO) techniques. 5G massive MIMO antennas typically contain 100 to 200 antenna elements, but the 6G era will introduce extreme massive MIMO, which will support 1000 to 2000 elements in new mid-band antenna arrays. By packing up to 10 times as many antennas on an array of the same size, we can send many more streams of data simultaneously.