A more modern approach to lowering the cost and complexity of extending cellular signals indoors will help drive a new generation of private cellular networking within the enterprise.
A long-time pain for many businesses been dealing with poor indoor cellular coverage. And one we’ve all experienced.
Outdoors, cellular signal strength is typically strong as obstacles and interference that impede transmissions are few and far between. But once inside a hospital, office or warehouse, cellular signal strength bars fade fast.
Outdoors, cellular service from the likes of Verizon, AT&T and T-Mobile have relied on big macro cellular towers. But indoors it’s a different story.
Today, many of the85 billion square feet of floor space across millions of buildings in the United States is either served by “outdoor-in” coverage from nearby macro towers owned and operated by mobile network operators (MNOs) or indoor coverage using elaborate distributed antenna systems (DAS).
Neither of these methods have worked particularly well from a performance, cost, or complexity perspective. Enterprises are now seeking a simpler and more cost effective indoor cellular wireless approach that supports an architectural framework closely mirroring their existing wireless LAN (WLAN) network.
Fortunately, more modern way to deal with this problem, called neutral host networks, is gaining tremendous traction as private cellular networks within the enterprise take hold. Private wireless networks make use of newly available unlicensed and shared spectrum, such as a Citizens broadband Radio Service (CBRS), recently made obtainable by the FCC and other telecommunications regulatory bodies around the world. Neutral host networks leverage this new spectrum along with the existing IT infrastructure companies already have in place for Wi-Fi access and computer networking services.
The Death of DAS?
To cope with indoor cellular coverage issues, companies, for years now, have opted to install discrete DAS networks– a complex array of cellular antennas, dummy radio heads and back-end equipment or base transceiver stations that require a totally new set of cabling to be installed in the building. The cellular signal is usually distributed throughout the building using and extensive network of fiber optic, coaxial or ethernet cabling. In this model the cellular access points don’t provide any signal processing but relay the signal to a base station located at a central hub. All this equipment is typically unique to a cellular carrier, making the solution extremely costly and complex to deploy and upgrade.
Giving birth to neutral host networks
Unlike traditional models, neutral host networking allows multiple parties – both private and public – to securely share the same private LTE/5G wireless infrastructure and backhaul IP network infrastructure within an organization. Doing so provides wireless connectivity to a wide range of MNO subscribers with the goals of increasing public cellular coverage and capacity while dramatically reducing capital and operating expenses using a shared network infrastructure approach. NHNs can be configured to dedicate individual “slices” from their network to public MNO subscribers, without disrupting existing service level commitments to critical enterprise applications.
Enterprise neutral host architecture (source: Celona)
Neutral host networks utilize so-called small cell access points. These indoor small cell-based neutral host networks offer a significantly reduced footprint, lower cost, and higher flexibility than DAS systems. Unlike DAS radio heads, each neutral host radio access node adds more capacity to the network, so as capacity demands increase more nodes can be added where demand is high.
The fundamental premise of neutral host is to increase the efficiency by sharing across the full infrastructure stack: spectrum, radios, cabling/network infrastructure and backhaul. This architecture allows for leveraging the design (RF and IP) efforts for multiple operators and even private networks – further improving the cost efficiency.
DAS networks are significantly more expensive than neutral host networks with small cells. The price differential stems from the need to use fiber-optic cables to connect each radio head to a central hub, the development of the hub itself, and the placement of the cellular base stations. As such, the implementation of a DAS network in a large venue, like a football stadium or hospital can often cost millions of dollars more for all the necessary DAS equipment, along with the tuning and optimization that will be required afterward.
Using the unlicensed general authorized access (GAA) tier within the CBRS standard, companies can now own and operate their own private cellular network without having to purchase expensive spectrum licenses or enter complex carrier contracts. This same network can be used for neutral host network services to expand public carrier cellular services indoors. Instead of deploying a variety of different equipment from different carriers. Small cells are used to broadcast different cellular carriers signals with traffic securely tunneled to the mobile core network of each respective MNO.
Also, neutral host networks represent a viable new option for “greenfield” deployments where there is no existing DAS in place, or the existing DAS is end-of-life. They can also be designed and deployed to complement existing DAS environments by providing additional cellular capacity and coverage using the CBRS band and the existing enterprise network infrastructure to connect to MNO networks.
For big telecom providers, a neutral host gives carriers easy access to a good RF footprint without incurring additional deployment expenses– attracting new business customers that require local connectivity to enterprise as well as mobility into the public network for ubiquitous access by leveraging existing infrastructure already in place and utilizing new CBRS spectrum.
Still, neutral host delivers a range of compelling benefits to enterprises trying to improve indoor cellular service including:
- support multiple MNO subscribers on the same wireless network,
- lower costs to design, acquire and operate enabling deployments at scale,
- full control over the network configuration and devices that connect,
- guaranteed QoS per application across a myriad of private use cases, and
- high degrees of privacy and security for critical infrastructure connectivity.
- In 2022, neutral host networking is poised to be the killer application for private wireless. With them organizations can now begin realizing all the inherent benefits that cellular technologies possess while also maintaining explicit control over the infrastructure that has historically eluded them.
