New wireless technology extends 5G value proposition indoors

Since most 5G networks are deployed using the 3.5 GHz band, they are likely to be affected by indoor environments because outside-in cannot provide adequate indoor coverage in mid- and high-bands, 3.5 GHz, and millimeter wave (mmWave).

Indoor wireless solutions are critical to the success of 5G in both consumer and enterprise markets. However, traditional solutions such as distributed antenna systems (DASs) do not support frequencies above 3 GHz and require significant retrofit engineering work to increase their capacity.

Growing network capacity demands and costly field infrastructure upgrades are driving infrastructure providers to invest in other innovative technologies.

A new wave of technology

ABI Research said some of the revolutionary technologies include distributed massive multiple-input multiple-output (mMIMO), radio striping, holographic beamforming (HBF) antennas, pCell technology, open radio access network (RAN) DASs, and reconfigurable smart surfaces (RISs).

Among these technologies, distributed mMIMO, HBF, and pCell are already available and are expected to be deployed on a large scale in 2023.

“Distributed mMIMO integrates mMIMO into indoor systems to achieve gigabit connectivity and sustainable network capacity expansion. Tailored for mmWave and software-defined antennas, HBF antennas adopt the lowest possible architecture in terms of size, weight, power and cost (SWaP-C), which are recognized as important considerations for network operators in denser 5G networks. pCell technology exploits interference in wireless networks through large-scale coordination between distributed transceivers and synthesizes a cell for each user. “It exponentially increases spectrum capacity with uniform high data rates across the entire coverage area,” explained Fei Liu, industry analyst for 5G and mobile network infrastructure at ABI Research.

“The move towards 5.5G Open RAN DAS could be another technology where there is an open interface between the Radio Unit (RU) and Virtualized RAN (vRAN) functions running on cloud infrastructure, thus reducing the number of transmitter elements and hence the associated power consumption, solving one of the main issues facing network operators. In the long term, RIS and Radio Stripes are seen as promising for improving indoor coverage,” Liu added.

RIS is almost passive, has no power amplifiers, and does not transmit new waves. Therefore, power consumption is much lower. Radio striping is another technology that promises to improve network quality and performance while simplifying network deployment.

"Academic research on RIS has been going on for several years, and now it is time for industry players (including vendors and network operators) to actively participate and provide clearer feedback on which directions to prioritize. RIS needs time and experience to become a revolutionary technology." - Liu Fei