Factoring in the cost and time to implement good in-building cellular coverage.
When is Fiber needed?
Fiber is typically used in an Active DAS to connect the cellular signal source to remote units, which in turn connect to antennas placed throughout the building to distribute the signal. Fiber has advantages in the high volume of data (bandwidth) it can transport, and in the distances that it can support between the source and distribution point. It can be 100s of meters, or more. If you need to provide better cellular service in a stadium, or an international airport, or for 70,000 attendees at the Kentucky Derby, or a huge trade show with a hundred thousand attendees, you have a capacity issue and you need to install an Active DAS with fiber. An Active DAS is a great solution for good cellular service throughout a shopping mall over a million square feet like The Galleria in Houston or Tyson’s Corner in Virginia, or throughout a high rise like One Meridian Plaza in Philadelphia or The Franklin Center in Chicago, and the distances from point to point, snaking through the space, can be quite large.
When is Fiber not needed?
A large percentage of your buildings are in the range of 500,000 square feet (generally called the middleprise) with several hundred to a few thousand occupants, a traditional Active DAS with fiber is rarely needed to provide the quality of service required for phone calls, video, engaging in social media, or the use of mobile apps by building occupants. Even cellular-based IoT applications – like a more reliable connection for POS/payment processors, video feed from security sensors, or vending machines with remote management – don’t require the heavy lifting of the bandwidth and distance provided by a traditional Active DAS with fiber. There are hybrid solutions that will provide the cellular coverage needed that are a much better fit at a fraction of the cost, and can be installed in weeks rather than the months or longer that it takes to install an Active DAS.
The cost, the installation time – what’s the best fit?
There are fixed upfront costs to install an Active DAS with fiber, regardless of the size of the installation. These costs are much more palatable when amortized over a very large space, versus a medium to small one.
The variable costs of Fiber are also considerable compared to the Ethernet cable that is used with some hybrid DAS systems. Texas-based Cellular Signal Solutions installs in-building cellular solutions using a variety of technologies depending on the best fit for the facility. James Parker, Project Manager at Cellular Signal Solutions provided the comparison of fiber versus Ethernet cost installation in the chart below:
|Billables for installing fiber|
versus Ethernet cable
for Active DAS
|Ethernet (CAT 6) for Active DAS Hybrid|
|Cost per linear foot (typical)||$2 – $4||$.30 – $.35|
|Power cable run per linear foot (needed to provide power to the remote units when fiber is installed)||$1.00||$0 not needed|
Headend cost is another important factor. Most Active DAS systems are somewhat modular, so price varies considerably. According to Parker, the headend of an Active DAS may start around $10-20K, depending on the vendor, features, bands, SISO vs MIMO, and how many carriers need to be covered in the building. For just two, such as AT&T and Verizon only, it might cost $15K. If the building needs all major carriers including T-Mobile and Sprint, the headend might easily cost $20-30K.
Remotes. In an Active DAS the headend and fiber are only parts of the solution. Each string of antennas is driven by what is called a Remote Unit, which is connected via fiber to the headend. Like the headend, a remote’s pricing varies considerably based on many factors, but are typically in the $2-5K range each.
When installing an Active DAS, contracts must be negotiated with each carrier that will be providing signal on the system. Contract negotiations alone can take months before the system can be turned on. It’s not uncommon for one or more carriers to completely avoid a DAS connection.
An Active DAS Hybrid, such as Cel-Fi QUATRA that been approved by the carriers for use on their networks, requires no further contract or authorization from the carriers to install. QUATRA installation can be done in a few days or a few weeks, depending on the size of the installation and current state of facility construction.
What about 5G?
If massive machine-type or ultra-reliable low-latency communications – such as enabling smart cities, major asset tracking, smart utilities and grid control, robotics, geofencing or wearable healthcare monitoring – won’t be important applications in your facility, you probably won’t need 5G connectivity for many years to come.
Expect to see 4G LTE remain the dominant coverage technology for end user voice and data for the foreseeable future. The most sensible 5G strategy for a middleprise building owner is to pick equipment that will withstand a transition from 4G LTE to 5G. For a more in depth discussion of 5G, please see this article: How Should Building Owners Be Preparing for 5G?
Cel-Fi QUATRA Active DAS Hybrid – a better fit?
There is no one size fits all solution for in-building cellular coverage. And there are endless pages of technical and use case information on the subject, enough to overwhelm any building owner trying to determine the solution that would be the best fit with the best ROI for a facility.
That being the case, of course cost and ROI must be important factors to consider, as well as installation time, maintenance requirements, and the flexibility and capabilities of the system for the uses needed on an immediate basis and over time.
For buildings or sections of buildings from 50,000 to 500,000 square feet, an Active DAS Hybrid such as Cel-Fi QUATRA offers the flexibility and coverage at a cost-point that fits the budget of most middleprise facilities.
QUATRA combines the best of active DAS and Cel-Fi technology that has been widely adopted by carriers around the world, delivering a scalable solution that provides configurations for single or multi-carrier environments. Options are available for off-air mode or via integration with carrier small cell to create a Supercell. Click here for insights on Supercell implementations.
Cel-Fi QUATRA distributes the carrier signal over Ethernet cable so fiber is not needed. It leverages Power over Ethernet so there is no need to run additional power cables to the remote units which increasing the ease and speed of installation while reducing cost. Nextivity also offers a remote management platform called Cel-Fi WAVE to all partners and customers, so installs can be monitored and managed without the need of costly truck rolls, facilitating Service Level Agreements (SLA) not previously possible.
Click here to watch a video and download the case study that showcases a hybrid installation in a New York food hall that needed help with cellular coverage.
About the Author
Joe Schmelzer is Senior Director of Products at Nextivity. He has developed a variety of products and industrial devices for chipset vendors, OEMs, and operators, including products for Qualcomm, Google, Verizon, AT&T, FirstNet, and T-Mobile. He was also a founding member of CTIA’s Wireless Internet Caucus. For more information, contact email@example.com or visit www.cel-fi-com