6G promises to merge the human and digital worlds

While the deploy­ment of 5G is still in its infancy, research centres and oper­at­ors are already work­ing on 6G. This tech­no­logy is expec­ted to be avail­able around 2030. What will it be used for and what will the bene­fits be? What chal­lenges will need to be addressed?

5G net­work tech­no­logy, known as mobile broad­band, was launched in France in Novem­ber 2020. It is gradu­ally being rolled out across the coun­try but will only be fully deployed by 2030. At the end of Septem­ber 2021, Arcep (the French reg­u­lat­ory author­ity for elec­tron­ic com­mu­nic­a­tions, posts, and press dis­tri­bu­tion) lis­ted some 22,600 anten­nas installed by the four oper­at­ors Bouygues Tele­com, Free Mobile, Orange and SFR. These sites trans­mit in the three 5G fre­quency bands (700–800 MHz; 1.8–2.1 GHz and 3.5 GHz). Motor­ways and main roads should be covered in 2025 and 2027 respectively.

Major mobile com­mu­nic­a­tions equip­ment man­u­fac­tur­ers and spe­cial­ist research centres have not waited to devel­op next gen­er­a­tion tech­no­lo­gies. If it takes a dec­ade to fully deploy a tech­no­logy, it takes at least as long to devel­op and stand­ard­ise it so that it is ready for the mar­ket. This explains why R&D work on 6G star­ted before 5G was even launched.

In its three fre­quency bands, the 5G mobile net­work already offers speeds 10 times faster than 4G. The 6G net­work is expec­ted to offer speeds 100 times high­er than those of 5G, thanks to the use of tera­hertz waves. In fact, the fre­quen­cies alloc­ated to 6G are between 100 GHz and 30 THz.

How­ever, these very high fre­quen­cies pose some prob­lems research labor­at­or­ies are cur­rently try­ing to solve. In tele­com­mu­nic­a­tions, the lower the fre­quency the fur­ther it car­ries and the lower the through­put. A high­er fre­quency does not carry as far, but with a bet­ter band­width. There­fore, we need to find a way to boost power of 6G to improve its per­form­ance over dis­tance while main­tain­ing high bandwidth.

In sum­mer 2021, the South Korean com­pany LG and the Ger­man research insti­tute Fraunhofer car­ried out a test and suc­cess­fully trans­ferred data over a dis­tance of 100 metres. The pre­vi­ous test had been car­ried out a few weeks earli­er by anoth­er Korean com­pany, Sam­sung, over a dis­tance of ~15 metres.

Anoth­er dif­fi­culty with very high fre­quen­cies is the loc­a­tion of the anten­nas. For the per­form­ance and speeds expec­ted from 6G to be achieved, the anten­nas must be spaced about 100 metres apart. While this does not pose a prob­lem of tech­nic­al feas­ib­il­ity in urb­an areas – apart from pub­lic accept­ab­il­ity – net­work cov­er­age becomes more dif­fi­cult to ensure in rur­al areas. This is why oper­at­ors are already devel­op­ing altern­at­ive solu­tions, in par­tic­u­lar HAPS (High Alti­tude Plat­form Sta­tion). In Janu­ary 2022, Air­bus announced that it was work­ing with NTT, DoCoMo and Sky to study the feas­ib­il­ity of satel­lite plat­forms that would provide wire­less con­nectiv­ity ser­vices to areas poorly covered by mobile tech­no­lo­gies, such as the oceans, air­space, and areas that are isol­ated or hit by nat­ur­al disasters.

After voice (2G), text and SMS (3G), data and apps (4G), the Inter­net of Things and indus­tri­al auto­ma­tion (5G), 6G aims to open up a whole new field of applic­a­tions. By integ­rat­ing the phys­ic­al and digit­al worlds and com­bin­ing ima­ging, loc­a­tion and arti­fi­cial intel­li­gence, these applic­a­tions will enable full immer­sion in digit­al space for vir­tu­al real­ity com­mu­nic­a­tion, inter­ac­tion and col­lab­or­a­tion exper­i­ences, as well as real-time tele-sur­gery, 16K video stream­ing, autonom­ous vehicles and digit­al twins.

Accord­ing to Nokia, 6G will bene­fit from advances in six key tech­no­lo­gies. Advances in arti­fi­cial intel­li­gence and machine learn­ing (AI/ML) will improve com­mu­nic­a­tion between two ter­min­als. Thanks to the tera­hertz fre­quency spec­trum alloc­ated to it, 6G will offer speeds up to 100 times faster than 5G. The net­work will be sens­it­ive to its envir­on­ment, objects and people, which will allow it to loc­ate and also meas­ure vari­ous para­met­ers (speed, tem­per­at­ure). The low latency of 6G (micro­seconds vs. mil­li­seconds for 5G) will make reli­able con­nectiv­ity pos­sible for real-time applic­a­tions such as autonom­ous vehicles or video con­fer­en­cing. With this con­nectiv­ity, new net­work archi­tec­tures will replace wire­line net­works and facil­it­ate the deploy­ment of cus­tom­ised and auto­mated net­works. Finally, 6G will be made with “secur­ity by design” in mind, incor­por­at­ing advanced secur­ity fea­tures right from the start.

The tech­no­lo­gic­al advances enabled by 6G will lead to dis­rupt­ive innov­a­tion in sev­er­al areas, includ­ing autonom­ous vehicles, industry 4.0 and telemedi­cine or health. This will trans­late into tan­gible eco­nom­ic oppor­tun­it­ies. In a recent state­ment, the Lan­nion tech­no­logy park (Brit­tany) estim­ates that the rise of “5G could rep­res­ent 20,000 new jobs and €15bn by 2025”. These fig­ures sug­gest that 6G will have a sig­ni­fic­ant impact.

How­ever, sev­er­al chal­lenges remain. The issue of stand­ard­ising 6G tech­no­logy on a glob­al scale raises ques­tions of sov­er­eignty and secur­ity. In addi­tion, the issue of pub­lic accept­ance is likely to come up again, sim­il­ar to the debates on health risks and the real need for such tech­no­logy that accom­pan­ied the launch of 5G.