Pioneering in-building 5G: Spectrum and architecture

In this Sparring Partners, we talked about 5G mmWave for in-building wireless (IBW) networks and about what we are learning from the research and initial deployments. What are the challenges and advantages of indoor deployments compared to outdoor ones? How does mmWave work alongside other wireless technologies in the enterprise? You can watch the Sparring Partners here but here some highlights from our conversation and exchanges with the live audience and the poll results.

Monica: What is special about in-building versus macro networks? Shirish: In-building is not a scaled-down macro network. Many people think, why can’t I just deploy a macro, just out of sheer size, power considerations, and so on, to get indoor coverage? You can try to shoehorn a macro network for in-building access, but this solution does not typically work. What we have found is that you must architect in-building solutions from the ground up. What we need is a ground- up design, and that is what we have done at Corning.

Some of the key challenges come up in scaling the radio. For example, if you have an in-building system that must cover 200,000 square feet, you will need upwards of 20 or 30 radios. That can even scale up to hundreds of radios, depending on the physical size of the site. The system must be scalable: that is one key thing. The other thing we have found is that it must be designed as a secure network from day one. In many instances, you may have a dedicated fiber backhaul to the enterprise, but, oftentimes, you don’t, and you are going over a public ISP. Connecting back to the core, you have to think of this entire system as being secure, especially given that

you don’t have any physical security. You have all the radios hanging off of ceilings, for example. Whereas in a macro network, physical security is built in.

Another thing we have found is that installation has to be easy. We design intelligent radios that discover themselves, they connect to their parent, and they authenticate and then download the software. It is almost a full security protocol.

The main thing to remember is that a macro network is designed to address specific challenges, such as high mobility, high speed, and massive MIMO.

The in-building environment is a lot more benign. You need to think about what really matters from a features point of view, such as power optimization. These things are critical and can change the way you design and think about networks.