Speaking at the recent Mobile Broadband Forum event in Dubai, Yang Chaobin, president of Huawei Wireless Solution, flagged numerous technology innovations and advances that take the traditional AAU (active antenna unit) found in Massive MIMO onto another level.
MetaAAU, developed by Huawei, incorporates ELAA (extreme large antenna array) technology supporting 384 antenna elements. It’s double the number of a traditional AAU.
“By introducing 384 antennas in the AAU, coverage can be improved by 3dB on both the downlink and the uplink, and the user experience can also be improved by 30%,” said Chaobin, “Energy savings of 30% can also be achieved.”
Better and greener 5G coverage required
Wireless network innovation is constantly needed, as operator requirements are not standing still.
Compared with the early days of 5G, for example, different deployment scenarios need to be catered for. Extending coverage into less densely populated areas is one requirement, as is coping with more demanding user-behavior and ensuring networks are greener. MetaAAU, explained Chaobin, can help industry address these pressing challenges.
The inter-site distance (ISD) in China and South Korea typically works out at between 300m and 600m. But as soon as operators start to roll out 5G beyond cities, the ISD picture changes. Average ISD tends to range between 700m and 1km in suburban and rural areas, depending on different geographical regions, although there are significant outliers. Some markets in Latin America have a suburban ISD of up to 1.5km. Operators urgently require better 5G coverage performance to simplify deployment of the next-gen tech.
New services also require higher downlink and uplink capacity. According to industry estimates, high-definition live broadcast video and 2x/3x playback speed require much greater downlink and uplink capacity than traditional video services.
Cloud based gaming, which is growing in popularity, also requires greater uplink throughput than normal smartphone-based mobile gaming. If attractive 5G user-experiences are to be guaranteed, appropriate quality of service is needed at the cell edge and indoors.
Moreover, there is growing commitment among carriers to build green networks, as well as increased urgency among industry bodies to combat climate change. The ITU, for example, has laid out a roadmap for ICT players to reduce greenhouse gas emissions by 45% between 2020 and 2030.
MetaAAU to the rescue with ELAA innovation
At first glance industry demands seem incompatible. On the one hand, operators want to continuously increase 5G coverage and capacity, yet on the other they want to lower power transmission and procure more energy-efficient network equipment. Another difficulty is that increasing transmission power of 5G base stations, even if operators were willing to do that, doesn’t improve uplink throughput.
“Some might ask why not design ELAA before, but there were lots of technical challenges,” said Chaobin. “We spent a huge amount of time solving these problems.”
If traditional materials found in antenna dipoles were applied to ELAA, for example, the weight would drastically increase, making it more difficult and expensive to install on cell sites.
Moreover, without miniaturized filters, ELAA dimensions necessarily become much bulkier compared with traditional massive MIMO antenna. Cell-site space is already constrained and operators don’t want to go through the lengthy process of gaining permission to occupy more tower space, which, in turn, increases maintenance costs.
Another challenge is that antenna elements in a traditional RF feeding network architecture are normally connected by cables, which are an inefficient way to transfer signals. If the antenna array doubles to 384 elements, the length of cable – along with the extent of inefficiencies – increases.
Through a series of hardware innovations, however, MetaAAU makes the transition to ELAA feasible and attractive. Using ultra-lite metamaterials, MetaAAU is around the same weight as the original 64T64R massive MIMO AAU. Adoption of Huawei’s compact wave filter also means MetaAAU dimensions do not require more space.
To address hardware energy inefficiencies, Huawei has adopted SDIF (signal direct injection feeding) technology. SDIF replaces cables with a more energy-efficient metal-type structure.
Aside from hardware innovation, MetaAAU introduces an adaptive high-resolution beamforming algorithm, dubbed AHR (Adaptive High Resolution) Turbo. It has various features, which, when combined, not only reduces wasted radiation energy but also cuts down on ‘noise’ that can degrade network performance.
Among the benefits of AHR Turbo is that it enables MetaAAU to generate extremely narrow beams that can precisely latch onto user equipment, as well as boost air-interface efficiencies by allowing beams to dynamically adapt to radio channel changes.
MetaAAU in action
MetaAAU has already been demonstrated on various commercial sites in China and has performed impressively in field tests. It provides 3dB better coverage and 30% better user experience than traditional 64T64R AAU, and when compared with the 32T32R AAU, MetaAAU improves coverage by 6dB and user experience by up to 60%.
Huawei has also demonstrated that transmission power can be reduced from 320W to 160W without decreasing coverage. What’s more, based on a 24-hour power consumption test on commercial networks, MetaAAU has shown that it can achieve a 30% energy saving compared with traditional massive MIMO AAU when serving the same coverage area.
As 5G deployment moves toward more scenarios, and carbon neutrality becomes the strategic goal of more operators, many regions around the world will put forward more requirements for energy saving. And let’s not forget that the coverage enhancement of 5G sites is greatly needed to make the user-experience better. It is believed that MetaAAU will have broad application prospects.
This content is sponsored by Huawei.