Why is beam management key to 5G?
5G beam management and massive MIMO enable mmWave
5G millimeter wave (mmWave) spectrum promises massive bandwidth and huge monetization potential for telcos. But 5G mmWave also introduces propagation challenges. 5G New Radio (NR) adds massive multiple-input multiple-output (mMIMO) support and utilizes beam management techniques to maximize throughput and device density to meet capacity needs for 5G mmWave User Equipment (UE).
Massive MIMO antennas, which increase data throughput and spectrum efficiency by adding transmit and receive elements to antennas, and high-frequency, high-capacity millimeter wave spectrum are both synonymous with 5G.
The goal of beamforming and companion technology beam steering is to transmit directly to a user and, in some cases, extend the range of RF transmissions. Beamforming techniques essentially shape radio waves through adjustments to phase and amplitude to make them more powerful and targeted. So instead of blasting coverage out throughout a cell, beamforming can direct coverage where it’s needed.
Beamforming algorithms can effectively determine the past transmission path to reach the end user letting an antenna array send data packets in different directions in a carefully orchestrated manner, which ups throughput and spectral efficiency.
Traditional macrocell deployment strategies won’t work for 5G mmWave communications. 5G mmWave’s shorter range and susceptibility to line-of-sight obstructions require a much higher density placement of small cells. Small cells using mMIMO and beam management provide a solution that enables carriers to maximize spectral efficiency.
Ericsson CTO Erik Ekudden explains the 3GPP evolution of mMIMO and beam management.
“Release 16 introduces enhanced beam handling and channel-state information (CSI) feedback, as well as support for transmission to a single UE from multiple transmission points (multi-TRP) and full-power transmission from multiple UE antennas in the uplink (UL). These enhancements increase throughput, reduce overhead, and/or provide additional robustness. Additional mobility enhancements enable reduced handover delays, in particular when applied to beam-management mechanisms used for deployments in millimeter (mm) wave bands,” he said.
R17 enhances features to support enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC) and massive machine-type communications (mMTC).
“The purpose is to support the expected growth in mobile-data traffic, as well as customizing NR for automotive, logistics, public safety, media and manufacturing use cases. The enhancements to existing features introduced in release 17 will be for functionality already deployed in live NR networks or relate to specific new requirements that are emerging in the market,” said Ekudden.
Making the business case for telcos to deploy 5G was the recent focus of research conducted by Bell Labs Consulting. Finding the revenue potential for mmWave involves deploying the technology strategically, according to Stephen Rose, Executive Partner, Bell Labs Consulting.
“We could see that most operators…would be able to achieve an 8 percent growth in their top line. That’s massive,” said Rose. “That would be a hard statistic to sniff at.”
Bell Labs was looking specifically at the 5G market in the U.K., but the business cases the research identified as “hot zones” suitable for 5G mmWave deployments are universal: indoor shopping malls, stadiums, train stations in urban areas, outdoor hotspots where large gatherings occur.
Bell Labs said that a range of 1,000 to 3,000 subscribers per hot zone is the right mix, at least for U.K. 5G mmWave deployments. Go too high, you run the risk of reducing your total addressable market, Bell Labs tells CSPs. Go too low, and you won’t have a viable business to build.