The limitless diffusion of portable smart devices with very high-resolution screens, of new data hungry applications and the future Internet of Things (IoT) that predicts billions of devices connected is opening a new age for internet high speed connections every time and everywhere.
Most of the data traffic is predicted to be wireless, but no existing wireless network at microwave frequency can actually sustain the dimension of the future data flux. The microwave spectrum is already congested and the available band are too narrow to support a multigigabit data rate.
Two main challenges have to be solved. One is related to the new generation of mobile networks to enable 5G. A high data rate at terminal level, maintaining the transmission at microwave range, can be achieved reducing the radius of a cell and increasing their density. This needs high capacity backhaul to feed a high density small cell networks in flexible and affordable manner.
The second challenge is the digital divide that severely affects low density inhabitant areas, namely rural and suburban, where fiber could not be deployed both for high costs and environmental constraints.
Millimeter waves have been unanimously recognised as the new technological frontier in wireless communications. Very wide frequency bands are available in different portions of the millimeter wave spectrum (60 GHz, 70-85 GHz, 92 -95 GHz and above), that could permit high capacity transmission.
Point to point (PtP) millimetre wave wireless links are already available, but when the number of links increases, PtP is not convenient due to frequency plan and deployment flexibility. The point to multipoint distribution (PmP) has the advantage to cover a wide area without frequency plan, with low footprint and arbitrary distribution of terminals. The transmission hub uses a low gain antenna that needs high transmission power to achieve a useful range. No amplifier was available to enable point to multipoint at millimetre wave above 40 GHz, because of the higher atmospheric attenuation and raining attenuation that require multiwatt power level.
The H2020 TWEETHER project introduces a new concept of wireless networks at millimeter wave enabled by a novel wireless point to multipoint distribution at W-band (92 – 95 GHz).
The TWEETHER consortium is simultaneously addressing a number of formidable challenges to build the first PmP at W-band to overcome the atmosphere attenuation by a novel high power Traveling Wave Tube (TWT)amplifier in the transmission hub. In addition, a full system at W-band is designed and build including a sophisticate synchronisation, a novel W-band MMIC integrated circuits. The target is enabling a new deployment scenarios, low cost approach, and the transfer of niche technology to a mass production.
In addition, the W-band has the great advantage to be lightly regulated for PmP distribution.
The breakthrough of the W-band TWEETHER system is making the PmP distribution possible at millimetre wave with up to 3.5 Gbps/km2 of area capacity over a few kilometres square.
