In-building mobile coverage now a critical utility

By Shirish Nagaraj, CTO, Wireless, Corning Optical Communications

Shirish Nagaraj is a member of WIA’s Innovation & Technology Council. Learn more about ITC here. These views are not a WIA endorsement of a particular company, product, policy or technology.

Providing connectivity inside buildings and venues solely using Wi-Fi is no longer adequate. People expect ubiquitous cellular coverage both outdoors and indoors, which makes mobile coverage a critical utility rather than just a nice-to-have tool.

Today’s real estate owners must accommodate social media and real-time communications, and online work collaboration platforms have to be accessible and work seamlessly in a mobile environment. Seamless indoor connectivity is also especially important considering the need for physical security and emergency calling capabilities in addition to voice and data connectivity.

But providing 4G LTE and 5G cellular signals indoors can be challenging and costly. Macro networks traditionally served buildings through propagation from outside, but newly refurbished buildings, especially those with green technology, have made it harder for cellular signals, particularly higher frequency signals, to penetrate windows and walls. The promise of 5G with ultra-fast and high-capacity connectivity will require networks to be custom-built within the premises.

In-Building Market

In-building wireless falls into two broad segments: public venues, including stadiums, arenas and airports, and enterprise facilities, such as healthcare, manufacturing, warehouses and hospitality. Public venue deployments are dominated by ruggedized distributed antenna systems (DAS) that provide good connectivity with all operators on the common frequency bands. Within the more price-sensitive enterprise environment, small cells and DAS have been deployed together to meet coverage and capacity needs inside buildings. Going forward, it will take the best of both the small cell and DAS worlds on a common platform to serve in-building wireless connectivity requirements adequately.

A common misconception is that all the large venues and buildings are already built out, but there is still opportunity in this market. In fact, large venues are an avenue for growth as many existing 4G solutions are aging and have limitations in terms of which frequency bands they support, as well as new requirements around 5G signal fidelity and higher order modulations. In addition, these venues have hotspot capacity needs – around the bowl of a stadium, executive suites or food courts, for example – where millimeter wave solutions can offload traffic in targeted use cases where a traditional DAS won’t work.

Today, indoor deployments still make use of both powered active systems and unpowered passive systems. The traditional delivery method using fiber-coaxial cable to antennas throughout the building tends to be ‘leaky’ in terms of power consumption, and venues that are increasingly interested in sustainability are looking toward more energy-efficient options. At Corning, we believe in the active fiber-to-the-edge story for in-building wireless to accommodate future upgradeability to support new frequency bands and new technologies such as 6G, and optimal energy efficiency. Corning provides a complete fiber-to-the-edge digital DAS solution with low-power radios, and we expect to see increasing demand for this type of solution in the future.

There remains much work to do to build out in-building wireless networks, and new technologies including Open RAN, Cloud RAN, Artificial Intelligence and Machine Learning are changing the landscape for these systems.

Cloud RAN

The underlying wireless infrastructure that has allowed transformational communications including voice, data and video, has evolved tremendously over the past several years. Recently, cloud RAN architectures have altered the traditional wireless topology indoors by aggregating baseband units in hubs with dedicated fiber runs to cell sites, which improves latency and performance while reducing costs.

CRAN separates hardware from software and allows cellular processing to be hosted on a general-purpose processor and run in a local data center or on premises inside the building or campus. This allows independence between the service provider and hardware appliance and software providers. In a cloud RAN, the signal source is replaced by on-premise servers running software.

Cloud RAN provides several potential advantages:

• In the in-building space, there are many requirements for latency-sensitive fronthaul, which essentially requires servers to be co-located or located on premises, especially as distributed units (DUs) become software-enabled.
• Enterprise-grade deployments have network security from the servers to the core network baked in.
• Operators can perform remote orchestration and monitor their systems in one place, whether for in-building networks, outside plant or outdoor macro networks.
• Artificial intelligence and machine learning can be implemented to make the RAN more intelligent and run RAN functions as well as some private network applications.

In addition, cloud RAN improves energy efficiency by allowing intelligent choices to be made about network usage.

Open RAN

The introduction of Open RAN (ORAN) could further revolutionize wireless networks while benefiting both mobile network operators and building owners alike.

Small cells were primarily built purposefully for a particular operator and that operator’s frequencies, while DAS can support multiple operators. What we are seeing now is a fronthaul split with ORAN that allows radio software functions from different vendors to occur in a small cell but run as a virtualized instance on a server. This allows radios from different vendors to work with the network core and for upgrades to happen via software as often as necessary, providing investment protection for enterprises that shoulder a large initial cost of deployment when installing in-building equipment.

ORAN gives rise to a variety of potential applications and benefits. For example, stadiums today are deployed with a large amount of base station hardware and radio hardware supporting hundreds of sectors. All of the associated RF processing expends a great deal of energy. Reducing energy usage with an ORAN-based interface between multiple BBU vendors, multiple RAN vendors and the DAS allows operators to co-exist in the same band. With ORAN, the total cost of ownership for neutral-host operators could be greatly reduced and should result in an increased ability for carriers to provide service in buildings and venues, leading to a better-connected experience for all.

A variety of players have been building ORAN-compliant solutions, including for the indoor environment, over the past five years. Adopting an open architecture with 5G ORAN could allow the neutral-host operator to experience extensive savings with the ability to use multiple vendor components.

Everon 5G

In a departure from single-carrier connectivity, Corning has developed a new indoor cellular coverage solution for high-density environments. The Everon Enterprise RAN 5G solution is a multi-operator, multi-band technology that provides end users with robust, reliable cellular coverage in venues such as hospitals, hotels, airports and other high-density environments.

Combining the signal source and distribution network allows elements to be deployed simultaneously, solving a two-part deployment challenge venues have faced in the past that requires them to wait for the operator to bring in the signal source after the distribution system is deployed. This game-changing solution reduces installation time by up to 75 percent and cost of ownership by up to 50 percent.

Everon supports both Multi Operator Radio Access Network (MORAN) and Multi Operator Core Network (MOCN) technologies. With MORAN, the radio is highly flexible and can support multiple frequencies, allowing use cases such as Operator A using one frequency and Operator B using a different frequency. Corning can light a private network on the same shared spectrum for multiple operators, allowing connectivity to the main operators while enterprises run their own private network using the same infrastructure. That coupled with AI/ML workloads will be very powerful over the next couple of years.