Most buildings have cellular coverage issues – dead spots, poor call quality, and low data rates are common issues that may impact subscribers of a single carrier or all of them. Extending quality cellular coverage throughout an entire building has always been a challenge for corporate IT and facility managers. This is particularly true for buildings ranging from 15,000 to 500,000 square feet, referred to as the “middleprise”. Good solutions exist in the SOHO context, and for stadiums, airports, and large shopping areas. But solutions for the middleprise have been either too complex or costly to install, limited in their capability, or over-engineered for the use case – making ROI a challenge to achieve.
There is no one-size-fits-all solution to cellular coverage inside a building, but thanks to recent technology developed specifically to meet the cellular coverage and budget needs of the middleprise, a variety of solutions are now available with different costs, performance, functionality, installation timing, and maintenance requirements.
Here are the available options:
Wi-Fi Calling (WLAN) – This can be a cost-effective way to extend coverage in small office environments where there is no available cellular signal, as calls are made over the Internet via the WLAN. However, it has limitations. Wi-Fi is a “best-effort” service over unlicensed/unmanaged spectrum, with an exponentially increasing number of devices and users jostling for connectivity. Without sophisticated network equipment the quality and reliability of service is highly variable. Service degradation is common, bringing businesses to a grinding halt. In fact, many facilities are now installing cellular failover, even when the WLAN is the main connectivity solution.
Small Cells – Small cells have a variety of vendor-specific names, come in many sizes, and support a variety of features. Fundamentally, they function as mini cell towers to help deliver a greater capacity of wireless signal indoors. Residential small cells, often referred to as “femtocells,” are more or less plug and play, but provide a relatively small amount of coverage, typically limited to less than 10 users (by “white list”).
For spaces under 30,000 square feet, some carriers offer small cells that can be installed by an IT-type person with some level of understanding of networking, Ethernet cabling, and Internet access. In buildings that are not an open plan, or have internal obstacles that block signal (enclosures, walls, impenetrable materials, multiple levels), one small cell may not be enough and may require professional RF (Radio Frequency) planning, and plumbing.
Active DAS (Distributed Antenna System) – Active DAS is most commonly used in large spaces (500,000 square feet and above) with a large number, and a high-density, of users. DAS requires considerable preparation through RF surveys and designs, planning and approvals, as well as significant installation time and cost, including trenching. As a result, it is rarely considered for middleprise environments. In a typical active DAS project, multiple carriers are involved, which can create delays for contract execution. Budget eight to12 months from start to finish for a DAS installation, and $2 to $3 per square foot of coverage. In extreme cases, the cost could be as high as $10 per square foot.
Smart Signal Booster – A Smart Signal Booster is a great solution for an office space up to 15,000 square feet. This should not be confused with older analog repeater technology or antenna technology that merely amplifies an existing cellular signal, with a variety of technology limitations that affect usefulness. Rather, a Smart Signal Booster is approved to boost the signal of an individual carrier, does not cause interference or add noise, and provides up to 1,000 times the gain of analog repeaters, which means it will provide a better-quality signal over a larger footprint.
A Smart Signal Booster can be installed in minutes by anyone and costs a fraction of the investment required for an active DAS or small cell solutions.
Active DAS Hybrid – There is a newer product category offering the quality of service of an active DAS with the ease of use and fast installation of the Smart Signal Booster. Active DAS hybrid solutions can support single or multiple carriers, and can be used on 3G / 4G / LTE networks. Unlike fiber-based DAS solutions, a hybrid can be installed in a few days or weeks by a system integrator, and is scalable up to 500,000 square feet for one or multiple carriers.
This system can be configured to amplify the signal from the carrier cell towers. If the outside signal source is insufficient, or if there are construction or environmental obstacles preventing the signal from penetrating into the building (such as mountains, surrounding high rises or LEED building construction), a small cell can be installed as the signal source. It is priced to fit the middleprise budget.
5G – There is a lot of buzz about 5G. If massive machine-type or ultra-reliable low-latency communications won’t be important applications in your facility – such as enabling smart cities, remote surgical equipment, driverless vehicle infrastructure, robotics, or geofencing – you probably won’t need 5G connectivity for many years to come. Expect 4G LTE to remain the dominant coverage technology for voice and data for the foreseeable future. The most sensible strategy for a middleprise building owner for preparing for 5G is to pick equipment that will withstand a transition from 4G LTE to 5G.
Citizen Broadband Radio Service (CBRS) – CBRS is a trending topic. CBRS is the name for the cellular frequency made available for public use in the 3.5 GHz spectrum. There are two implementations of CBRS that are meaningful. The first is Private LTE. A CBRS-based Private LTE network could be installed to improve communications in a large enterprise space. Private LTE also offers IT administrators greater control over access and security.
The second use for CBRS is neutral host network, or NHN. There is a substantial amount of misleading information in this area from a variety of equipment vendors about this. The NHN will be advertised to offer “Wi-Fi-like” cellular service in building. The challenge here is that the carriers have no incentives to support these initiatives, so it’s extremely unlikely it will see broad adoption in the market.
Cellular coverage throughout corporate facilities is no longer an option. The need will only increase as cellular devices replace desktop phones through the company and as IoT installations become more prevalent for operations, security, building maintenance and connections to outside vendors. To choose the best technology, it is essential to first have a good understanding of the level of cellular connection the corporation needs now and in the future.