The long-held promise of 5G connectivity is coming closer to reality. Verizon recently launched its 5G Home service, which empowers consumers in test cities to forego cable and fiber optic internet connections and instead rely solely on wireless delivery. Verizon isn’t alone in building up and hyping its 5G offering. Each of the major U.S. cell carriers has deployments that are ready to go or in production. (Full disclosure: ADRF has a partnership with the four major U.S. carriers.)
However, for 5G to become ubiquitous, providers must overcome considerable infrastructure and cost challenges. There are only so many cell towers in the U.S., meaning that carriers must be more creative and efficient in how they use the physical space already in place or invent new ways to increase their points of presence (i.e., locations where hardware provides signal).
This isn’t a small issue, and it is being exacerbated by protestors and legislator concerns. Across the U.S., from Palo Alto, California to Montgomery County, Maryland, citizens are decrying carrier efforts to implement small cell technology that can serve as the backbone of 5G. Small cells are considered necessary for 5G because the networks are likely to operate over millimeter wave frequency bands, which do not propagate as well over long distances compared to frequencies most commonly used for 4G and LTE. Even with the recent news of the FCC ruling to speed up deployment, it’s a very real possibility small cells won’t be the answer in some areas and carriers will have to find alternative options to increase their coverage density and capacity.
One technology that’s becoming more popular as a way to address the issue is Massive MIMO (multiple input, multiple output) antennas. MIMO has been available for years and is essentially a bundling of multiple antennas into a single box. This enables each cell tower to carry additional capacity, all powered by the same source and held on the same physical bar on the tower.
Massive MIMO, which goes beyond two antennas to up to 128 per box, is a logical extension of MIMO but one that’s only jumped from theoretical to reality in the past few years. This is a result of smaller hardware and improved software to meet the requirements of these powerful antennas. Most people consider only their phones and their carrier that supplies signal from “somewhere.” However, there is a massive software ecosystem behind the scenes that is controlling these connections. Companies offering network function virtualization (NFV) technology can alert carriers to increases in network traffic and automatically reroute as needed to ensure cell and data connections aren’t lost or reduced.
This offload and network shaping weren’t entirely possible without corresponding hardware improvements. If a network is limited by the volume of data that hardware can support, there is no way to offload. Antennas are simultaneously becoming more powerful and smaller, meaning that they can be combined into Massive MIMO arrangement and deployed on existing infrastructure (like towers). Sprint VP of Technology Ron Marquardt discussed this convergence at Mobile World Congress Americas.
A separate challenge relating to small cell and 5G is the high cost of a complete small-cell deployment for in-building cellular connectivity involving multiple carriers or multiple frequency bands. With LTE deployments, mobile carriers often pay the expensive upfront cost of deploying wireless infrastructure to large venues when it fits their network plans, closes a coverage gap or reaches a large number of customers. To keep costs down, they traditionally partner to deploy a distributed antenna system (DAS) that supports radio frequencies for all carriers and amplifies signal through corresponding antennas dispersed across the venue.
While small cells are generally considered the most cost-effective approach to building out 5G, there are times where a hybrid DAS solution is a better option. Small cells today only offer compatibility with a single mobile carrier or up to two frequency bands in a unit, which means if all mobile carriers opt into the network, it can create a substantial hardware cost. Smalls cells may be a viable option when a venue wants to build upon its existing wireless infrastructure, but they can be costly for a new venue requiring new wireless network systems. Research from Wireless Design and Development favored hybrid DAS over other forms of DAS implementations by 60%. Implementing DAS to feed the signal from all carriers through small cells can adequately cover in-building 5G networks at a more affordable cost.
5G will ultimately transform a number of industries. According to research firm IHS Markit (via MIT Technology Review), 5G could potentially generate over $12 trillion in revenue. However, there will be growing pains associated with network rollouts across the U.S., as the technological path of least resistance (small cells) continues to encounter hurdles. Massive MIMO and a hybrid DAS solution are a couple ways these issues can be addressed in order to meet the promise of 5G in every U.S. city.
