Consumer demand for bandwidth, small-cell densification, and 5G rollout plans are widely seen as driving investment in fiber optical distribution networks (ODN) to support mobile backhaul, but equipment vendors such as Ericsson continue to trumpet the benefits of microwave-based transport as 5G networks proliferate.

As discussed in a previous article by Glen Hunt, principal analyst in global telecom technology and software at Global Data, a combination of fiber and microwave deployments will likely remain the preferred option of mobile operators in the future, with fiber expected to be the first choice for connectivity.

At the same time, the deployment of fiber will become a growing concern as 5G rollouts intensify, and it’s fair to say that fiber will not be easy or even possible to install in every location. That’s certainly the view of Shane McClelland, head of transport for the North American market at Ericsson, who made use of a blog post to explain why microwave transport is also perfectly able to handle the demands of a 5G radio access network (RAN).

However, McClelland also pointed out that not every microwave technology will have the capability to handle the demands of a 5G network. He noted that requirements include the ability to make efficient use of available spectrum, supporting 4096 QAM, for instance. It will also be important to support MIMO technologies, integrated Ethernet switching and IP routing functionality, hierarchical quality of service to enable network slicing, and advanced automation and intelligence.

Ericsson also recently published a report, titled "Ericsson Microwave Outlook," which emphasized the importance of obtaining the right spectrum for backhaul as well as access for the introduction of networks based on 5G New Radio (5G NR). The vendor highlighted the fact that the E-band (70/80 GHz), “is not only becoming an essential backhaul band of high global alignment, but together with the 32 GHz band, it will be an important prerequisite to facilitate the transition of some backhaul frequency bands to 5G NR access use.”

Ericsson said in its report that a combination of fiber and microwave solutions “remains a winning backhaul strategy for evolving 4G and developing 5G networks.” The next major threshold, the vendor said, is to reach 10 Gb/s everywhere.

“While the technology needed to enable this is already available, standardization and spectrum regulation changes will be fundamental to creating cost-efficient solutions,” the vendor concluded, noting that recent advances mean that artificial intelligence (AI) and machine intelligence — defined as the application of AI techniques to machine learning — “now offer techniques that leverage the expertise of microwave planners and engineers, allowing for management of larger, more complex and efficient microwave networks.”

Of course, Ericsson and rivals Nokia and Huawei Technologies also have long been selling microwave solutions to support 4G RANs, and it’s certainly in their interests to ensure that microwave remains relevant in the 5G era.