Recent FCC rules establishing the commercial use of the Citizens Broadband Radio Service (CBRS) spectrum within the 3.55 to 3.7GHz range (band 48) is driving enterprise interest in the use of cellular technology to enable connectivity for many digital initiatives that demand predictable performance, low latency mobility and reliable coverage in challenging indoor and outdoor environments within enterprise owned and operated facilities.
Using the unlicensed general authorized access (GAA) tier within the CBRS standard designation, companies can now, for the first time, own and operate their own private cellular network (also referred to as a 5G LAN) without having to purchase expensive spectrum licenses or enter into complex carrier contracts. This allows organizations small and large to begin realizing all the inherent benefits that cellular technologies possess while also maintaining explicit control over the infrastructure that has historically eluded them.
The emergence of new 5G LAN technology is widely viewed as an ideal solution for connecting vital and widely dispersed IoT systems and critical enterprise applications that cannot tolerate wireless network latency, roaming disconnects, or wild swings in network performance. Even more compelling but little discussed is using a private 5G LAN to enable neutral host services to solve the ongoing challenge of extending public cellular signals indoors.
Regardless of the underlying technology, wireless networks require ubiquitous coverage, high throughput capacity, and deterministic quality of service (QoS). Unfortunately, the current methods for delivering cellular connectivity within the enterprise often lack one or more of these essential requirements. Today, most of the 85 billion square feet of indoor space across millions of commercial buildings in the United States is either served by “outdoor-in” coverage from nearby macro cell towers owned and operated by mobile network operators (MNOs) or “indoor-out” coverage through the use of elaborate distributed antenna systems (DAS).
Neither of these approaches has worked particularly well from a performance, cost, or complexity perspective. In turn, enterprises seek a simpler and more cost-effective indoor cellular wireless approach that supports an architectural framework closely mirroring their existing wireless LAN (WLAN) network.
DAS solutions are often cost-prohibitive. These solutions require dedicated cabling and are restricted to addressing coverage for a specific MNO. In contrast private LTE, and soon 5G, networks can provide a seamless way to support enterprise-managed devices, as well as myriad BYOD and visitor/customer devices that are active subscribers of the MNOs in question.
Meanwhile, public cellular services have left companies with little to no control over the level of service provided. This has created a gap between the top end of the indoor cellular market directly served by MNOs and hundreds of thousands of smaller venues – opening the door to new approaches that remove complex business models and costs associated with the multi-operator cellular support.
NEUTRAL HOST
The emergence of small cells and private spectrum options (e.g., CBRS in the United States) has paved the way for a new network architectural model that delivers MNO network coverage and capacity within the same private LTE/5G wireless network where critical enterprise applications are also supported. This model is known as a neutral host network (NHN). Locations deemed to have weak signal strength from the macro MNO network or insufficient capacity under high-density situations are the ideal private enterprise facilities that can take advantage of NHNs.
Neutral host networking is a relatively new concept that, unlike traditional models, 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.
The fundamental premise of the neutral host model is the sharing of deployed network infrastructure components such as the campus switching and routing infrastructure, Ethernet cabling, rooftops, power, cabinets, lighting, and air conditioning. Active network sharing involves dynamic real-time sharing of antennas, access networks, transmission, spectrum, RF design, planning, and core network functions.
The role of a neutral host network is to leverage existing private LAN, WAN, and cellular radio network infrastructure to propagate both MNO and private enterprise 4G/5G signals. This architecture creates enhanced signal strength or capacity in locations where coverage is lacking or at certain venues where it doesn’t make sense for each MNO to deploy and manage a separately owned wireless network.
The underlying benefits of neutral host networks are plentiful and include:
– Providing added cellular coverage in low coverage areas;
– Increasing capacity in congested locations;
– Delivering reliable cellular connectivity to occupants within a building that, to users, is seamless and indistinguishable from public cell tower access;
– Enabling cellular coverage within venues with limited equipment space;
– Increasing wireless coverage at significantly lower infrastructure costs;
– Simplifying the deployment and ongoing operation of indoor MNO signal propagation;
– Servicing multiple cellular networks, public and private, using a single shared and common IT infrastructure
SEAMLESS ROAMING
For users of the network, a neutral host network operates seamlessly with their MNO’s regular cellular network and will be entirely transparent to them. Accessing the neutral host doesn’t take any user input or action to roam into and out of the network, as roaming onto a neutral host network uses the same cellular roaming principles and procedures as roaming onto another RF band of a given operator’s network. This makes neutral host networks an ideal choice for extending the coverage of existing mobile networks, especially where coverage is limited or non-existent.
Neutral host networks add the ability to easily integrate private cellular access points to an existing IP network infrastructure to broadcast multiple signatures of different private and MNO networks, securely tunneling traffic directly to each requisite network operator’s mobile core. The illustration below shows how modern neutral host networks are being architected.
Most smartphones and LTE devices manufactured in the last three years are natively compatible with networks that operate in the private cellular spectrum frequency range (3550-3700 MHz for CBRS in the US, for example). Any such device with a public carrier SIM advertised on the private cellular spectrum can connect and use the MNO network services natively as if it were connected to a public MNO cell tower. No other free-to-use spectrum can accomplish this feat.
But perhaps the biggest benefit of neutral host networks is their simplicity and low deployment cost. Neutral host networks operate using a conventional WLAN framework to enterprise IT staff at a fraction of conventional alternatives’ capital and operational cost. Cellular access points connect the existing enterprise IT network to LTE/5G core services residing on premises or within a private data center/cloud environment. This eliminates the need for additional cabling and discrete equipment from each MNO required to authenticate service users.
While multiple use cases and applications are driving the near-term deployment of private LTE/5G network infrastructure within the enterprise, neutral host network services represent what looks to be the killer application and long-term value of private cellular technologies. Leveraging these new 5G LANs with neutral host capabilities provides enterprises, MNOs, and their customers a major market opportunity. The ability to now address a massive indoor cellular technology gap within the mid-market is an opportunity many have long waited for.
