Indoors Will Be 5G's Biggest Challenge

Indoor locations with their steel frames, insulation and treated glass have always been a coverage challenge for wireless operators, and that challenge will only be heightened with 5G deployments.

That's because 5G is made up of high-frequency transmissions that shorten its range, explains Heavy Reading analyst Denise Culver in new research. As she explains it, applications that need 300GB per second have to operate over 28GHz on 5G, meaning a signal range will be extremely short and easily interruptible by even a thin wall. (See An Indoor Battle Strategy for 5G.)

Seeing that wireless operators are talking up the power of 5G for ultra-reliable and low latency communications in settings like factories, industrial warehouses and underground mines, this could be a big problem.

Operators' go-to strategy -- distributed antenna systems (DAS) -- won't help either, Culver says, since they are complex, expensive and don't support 5G's bands of 3.5GHz or higher.

So what is the solution? Culver writes that indoor digitalization could provide a viable alternative for 5G indoors since it supports a range of technologies with high data rates, including multi-carrier aggregation and distributed MIMO, and is backwards compatible with 4G. These indoor digital networks could also give operators new revenue opportunities.

Huawei is one proponent of this strategy and has worked with operators to identify hotspots and calculate their potential ROI. Culver says they've "experienced hotspot identification accuracy of 85% and reduced ROI to less than four years using indoor digital networking solutions."

Small Cell Forum CEO Sue Mohanan has also talked up the importance of -- what else -- small cells for 5G coverage, although admits there are many challenges to overcome there as well. (See Sue Monahan: Small Cells Crucial to Indoor 5G.)

The great indoors, where consumption is highest -- and ever-increasing -- will be an important battleground for 5G, and one that operators can't ignore as they begin their trials of both fixed and mobile 5G networks. The new challenges will require new solutions that take into account coverage, reliability, latency and -- importantly -- monetization.

— Sarah Thomas, Contributing Editor, Telco Transformation