The RF Reality Of 5G Rollouts

Today, most of the hype around 5G is focused on innovative, new applications and technology advances such as virtualization, network slicing, and software-defined radios. But, as 5G applications evolve, and software continues to replace hardware, we can be sure of one thing: the antennas and cable connectivity at the front end of the radio access network (RAN) will not disappear. In fact, these very tangible network elements representing the air interface will become more important than ever.

The radio portion of the network is effectively the RF plumbing in a 5G network. This vital RF infrastructure for mobile wireless fronthaul must be deployed in addition to existing 4G, 3G, and 2G network technologies and alongside Wi-Fi, mission-critical radio, and other spectrum. Antennas and cables must be added to cell towers and rooftops that are already at maximum capacity. Antennas must offer more ports, support more frequency bands and provide more capacity while consuming less space. And, they must enable complex and power-intensive capabilities such as beamforming and massive MIMO (mMIMO).

Key RF advances have been made

We’ve already made tremendous progress toward resolving the considerable challenges associated with 5G network requirements:

• Active Passive Antennas (APAs) interleave active and passive components in a single antenna to support passive 4G and active 5G transmissions with no compromises to performance, no additional leasing costs, and the lowest possible visual impact.
• For wireless (microwave) backhaul applications, dual-band microwave antennas support high-capacity, low-latency 80 GHz E band transmissions as well as higher availability 15 GHz, 18 GHz or 23 GHz transmissions to make microwave a viable alternative to fiber for 5G backhauling in urban areas.
• MIMO beamforming antennas offer up to eight ports and support pivotal new frequency bands, including 3.5 GHz, which will play a critical role in the evolution to 5G.

As we head into a new year and a new decade, RF solution providers must now anticipate and resolve the next phase of RF plumbing challenges in 5G mobile networks.

All RF solutions must be 5G-ready

The first step is for RF solution providers to ensure their entire portfolios are 5G-ready.

Spectrum-wise, it is crucial for RF solutions below 6 GHz to support the 3.4 GHz to 3.8 GHz range. Consequently, coaxial feeder and radiating cables must be no more than 1 ¼ inches in diameter to operate in the 3.5 GHz band and support MIMO to ensure 5G-readiness in challenging indoor locations, such as buildings and tunnels.

Above 6 GHz, microwave antennas and waveguides must operate in the 26 GHz and 28 GHz range to support fixed wireless access and be considered 5G-ready.

Complex technical challenges must be addressed

Because spectrum is money, RF solution providers must continue to develop solutions that make the most efficient possible use of this valuable and finite resource.

RF is not a miracle. Resolving legacy challenges, such as interference and site densification, will be increasingly difficult as antennas support more bands in smaller form factors, and overall network data throughput is directly affected by antenna radiation patterns.

And, those form factors will become extremely small. As we push further into millimeter wave technology, we must develop miniaturized antennas that are only 130 to 150 mm (5 to 6 inches) in diameter to transmit the very short wavelengths that occur beyond 100 GHz. Developing these antennas will be challenging from an RF perspective and a materials science perspective.

We will need to deploy antennas everywhere, meaning a stealth 5G approach will be crucial. Very complex RF equipment must be designed to deliver maximum performance while hidden in smart poles, street furniture, building furniture and other locations where it is not recognizable.

We must also consider how 5G and broadcast technologies can be combined. For example, an intelligent, 5G-ready broadcast overlay network could be used to stream the same content to many 5G end users and devices in different 5G cells to help offload the 5G network. The key will be to leverage both sides of the content delivery equation.

Partnerships with RF experts will be essential

To maintain their value to mobile operators, original equipment manufacturers (OEMs) will have to ensure their over-the-air network solutions deliver the extended mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC) that 5G applications require. This requirement, and the need to scale 5G solutions for vertical and enterprise market segments, means OEMs must partner closely with RF experts. Otherwise, mobile operators and their OEMs risk being reduced to mere data pipe providers, challenged by agile startups and web-scale players targeting 5G opportunities.

Ericsson’s recent acquisition of Kathrein’s antenna and filter business confirms OEMs recognize the strategic importance of RF technology to 5G and beyond.

The entire RF chain must be strong

As we continue to evolve mobile networks, it’s critical to remember they are essentially a chain of connected elements. And a chain is only as strong as its weakest element or link.

RFS is a strong player in the industry, delivering end-to-end RF solutions to ensure the strength, integrity and quality of the entire RF chain. In the race to 5G, this distinctive advantage will be crucial for OEMs and mobile operators around the globe.