Enterprise densification efforts continue to challenge carrier ROI models, though a combined approach using small cells and DAS could provide an answer.
Editor’s Note: The RCR Wireless News Reality Check section is where C-level executives and advisory firms from across the mobile industry share unique insights and experiences.
The “middleprise” continues to be plagued with dropped calls, black holes, slow data speeds and poor hand offs. These challenges persist despite all the sophisticated technology that has been available to provide enterprise-grade indoor cellular coverage in commercial buildings, particularly for this market.
According to the U.S. Energy Information Administration, there are 1.5 million commercial buildings in the U.S. that are between 10,000 and 200,000 square feet in size. Carriers face real world challenges associated with resolving the indoor capacity and pervasive coverage demands of customers within these smaller commercial venues. This holds true even after all the backhaul and fronthaul technical issues are sorted out; platforms, architectures and standards clearly defined; spectrum assigned; and operating expense allocated.
When it comes to delivering uniform in-building coverage, there are a number of issues – ranging from hardware and labor costs to skills shortages – that have historically stood in the way of large scale densification with an acceptable return on investment for the carrier and lower total cost of ownership for the middleprise building owner or lessee. This legacy is manifesting strong signs of change with new and affordable hybrid-based technology advancements specifically tailored to meet the coverage needs of this market.
The hardware challenge
The availability of hardware has always been a challenge. There has been no single solution that has met all the criteria to adequately satisfy the indoor cellular requirements of enterprise subscribers. To resolve this challenge, small cell manufacturers are evolving their portfolios to include several technologies, such as Wi-Fi and multicarrier capabilities. Still, for the most part, venues such as hospitals or hotels or multitenant office buildings must rely on multiple solutions that address different needs – from administration staff to common areas.
While traditional distributed antenna systems can resolve indoor coverage problems and add capacity when combined with a fiber-fed, in-building base station, implementation is usually far too costly for middleprise landlords or tenants with venues under 200,000 sq. ft. An alternative is to bring in multiple small cells from the same carrier or a neutral host where requirements dictate different carriers. As might be expected, this comes with its own set of issues, including adequate installation and planning experience, overlap of coverage footprint and the potential of interference.
The question of densification
A venue that has installed multiple small cells will often find that small cell signals are not effective at the perimeter of the building where the macro (outdoor) signal dominates. When devices inside the building are drawing from the dominant macro signal, only partial network densification is accomplished for that building at best.
To truly densify a venue, devices within a building must draw signal from the signal source (small cells) installed in that building. This takes the burden off the macro network and ensures no “traffic-load” conflict between macro and in-building small cells. To ensure an optimized, unbiased outcome, the proper location of the installed small cell(s) is critical so that cellular devices/sensors aren’t tempted to surrender to the macro network, but remain loyal to their in-building small cell signal source.
As highlighted, the greater the small cell population in a single venue, the greater the potential of interference and substandard performance of the small cell investment.
A small cell/DAS hybrid is a new approach to resolving these potential complications. A small cell is generally centrally located on-premise and connected to an intelligent DAS hybrid designed specifically for smaller spaces, with remote radio units that can be readily placed in the very best locations for the building construction and ultimately for cellular use. By connecting a small cell to an active DAS hybrid, users can achieve uniform coverage and capacity distribution for venues up to 200,000 sq. ft. at a far lower price point than a traditional DAS, while eliminating potential interference and macro network dominance.
This small cell/active DAS hybrid creates what is termed a “supercell” (i.e., a large single cell versus multiple small cells) that provides uniform access to the capacity introduced by the small cell. Supercells are inherently uncomplicated from a planning and deployment point of view and are far more resilient to the potential of interference or performance degradation considerations.
Skills in short supply
Adding indoor cellular capacity and coverage is more complex than a Wi-Fi deployment model since installers must grapple with countless issues related to RF designs, cabling, backhaul, configuration and potential interference. In the case of classic DAS installations, an RF design model must generally be created in IBWave or similar software for each site – a costly and time-consuming engineering process requiring advanced technical skill sets.
While RF engineers and trained technicians are in relatively short supply, IT departments of medium-size enterprises are typically manned by competent individuals with basic networking, cabling and technical troubleshooting skills. With the right technology in hand, this readily available IT workforce can be mobilized, without costly truck rolls, to support massive scale in-building densification.
The right mix of technologies that match IT department skill sets are now becoming available and being readily adopted.
Small cells with self-organizing network capabilities are now emerging on the market and vendors have been developing small cell solution strategies that mitigate interference related issues. Certain carriers currently allow their enterprise customers to directly purchase up to three small cells for installation by their own IT teams.
For the IT department deployment model to work, the hybrid intelligent DAS mentioned above must readily connect and integrate with these small cells. It should ideally also support SON configuration capabilities to further enhance overall in-building venue performance.
Unlike the installation of fiber or coaxial cabling, Ethernet-like installations are commonplace. Hybrid solutions incorporating Ethernet distribution to the remote radio units have a distinct cost and ease of installation advantage.
In a hybrid supercell, these technologies and cable-media are seamlessly integrated together, readily empowering the IT workforce and effectively overcoming the lack of sufficient manpower and skill sets that have traditionally delayed enterprise in-building densification efforts.
The cost factor
No technology challenge can be resolved en masse if the costs are out of kilter. Carriers are often willing to subsidize solutions for large-scale customers (usually in the form of a classic DAS), but not for medium-size enterprise customers as the ROI is just not sufficient to justify the cost. In these cases it is understandable carriers want to transfer the burden of cost to the building or business owner, including the cost of installation (which can be far more expensive than the hardware itself).
A supercell mitigates the cost issue in several ways. With IT personnel installing a carrier-approved small cell tethered to an intelligent hybrid DAS, the high costs of RF engineering, installation and optimization are minimized. The cost of the system is further reduced by using the hybrid DAS as it can provide coverage for the same size space that would otherwise require several small cells, but at a markedly lower cost. Thus, a supercell delivers a compelling TCO for middleprise budgets.
Some final words
With the continued high demand for capacity and pervasive coverage by the middleprise, densification is a critical response issue for carriers. At the same time, resolving densification challenges has historically been a balancing act between available resources, cost, time and ROI.
In the case of classic DAS for the middleprise space, carriers have simply not been willing to finance or subsidize their exorbitant costs. Multiple small cell installations represent a partial solution to building architecture and construction materials, customer performance requirements and timelines.
It is clear that the cost and installation complexity of indoor cellular solutions need to come down sufficiently for enterprises to commit to funding. The good news is there are now hybrid options available in the market that can enhance carrier portfolios to provide better service to the valuable middleprise market.
Werner Sievers, CEO of Nextivity, is a veteran of the wireless industry. He has extensive leadership experience at internationally-focused semiconductor and wireless venture-backed startups and emerging growth companies, spearheading the successful development, launch and acquisition of disruptive technologies and businesses.
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