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.