The mobile industry is on the cusp of an infrastructure headache as a result of 5G. Everything, from large scale IoT deployments to self-driving cars, could eventually be powered by the next generation of cellular technology. Yet, there’s a huge technical challenge to be overcome before that can become a reality.

At MWC, there’s been a lot of talk about the hardware needed to not only make 5G a commercial success, but also to deliver on its promise for the future. However, the more pressing question on everyone’s lips should be how carriers can address the next generation of infrastructure roll outs in the most efficient way, particularly as the new antenna systems that 5G will depend on, present their own hurdles. After all, while there’s no doubt that high performance antennas will necessarily support future mobile deployments, this will only contribute to the telecom site nightmare that carriers have faced for some time.

Where do we put new active antennas?

Adding new antennas to existing cell sites is far from straightforward, despite the fact that this issue has been building with temerity, in severity, for several years. As the average site has to support many different antennas and bands for a variety of different purposes and carriers, introducing new models is a nightmare.

It’s not a problem that can easily be addressed by adding extra sites either. Trying to acquire new locations to erect antennas is a long and complex process, which makes it easier to work with sites that have already been secured. But that takes us back around in a loop: with the move to 5G, this issue is going to hit critical mass, particularly in dense urban locations where sites are already overcrowded.

This is the very heart of the industry’s infrastructure headache and it’s not easy to fix. A big part of the problem is that there’s no escaping the need to implement active antenna systems in order to deliver on 5G. Crucially, since 4G and 5G will exist side by side, and as LTE-based systems will keep evolving adjacent to 5G, this removes the option to rip out and replace existing equipment.

Due to these challenges, there’s a pressing need to find new ways to deploy 5G-ready active antennas onto existing sites, in a way that won’t compromise the infrastructure that’s already in place. So, what’s the best way to make this a reality? Well, carriers have a couple of options.

Finding a workaround

Since space is at such a premium, the first option is to combine existing passive arrays, or “stack” them, to create space for new active antennas on the cell site. It’s an approach that would achieve the desired goal, but it comes with several performance trade-offs.

Since an active antenna already provides a degree of system efficiency by integrating both the antenna and radio components into a single unit, many carriers are looking to take this concept one step further with what’s called an Active Passive Antenna system, which innovative hardware vendors are capitalising on.

The best of both worlds

Active Passive Antenna systems combine a 5G active antenna with a passive base station antenna that’s already being used for legacy networks. For carriers, it’s effectively a two-in-one system, housed in the same form factor as what they’ve deployed before. It’s simplified and streamlined, introducing a layer of active antennas to existing macro sites, without having to increase the overall antenna count per sector.

What’s important about this latest industry development though, is how it’s helping to shape the way hardware is managed and upgraded in the future. Since we’re likely to see several generations of active antenna technology in its lifetime, this has understandably created concerns about the total cost of ownership associated with the new antenna systems carriers choose to deploy. Modularity is being built into the latest hardware approaches as a result, particularly in Active Passive Antenna systems, which means that new active antennas can be deployed in stages. 

For example, the passive element can be installed at the cell site first and be operational immediately, with an active antenna added to the unit later on. This approach is the future of mobile infrastructure and lets operators adopt a “pay as you grow” strategy, spreading up front cost as well as streamline maintenance and upgrading in the future.