Metropolitan Communications BDA vs DAS: What’s the Difference?

BDA vs DAS Exton, PA

No matter where you’re working, it’s important that you and your team are always equipped with a dependable wireless communications system. When communications are less reliable, day-to-day operations are less effective too. If your enterprise has unreliable in-building wireless signals, Metropolitan Communications is here to help with BDA/DAS technologies.

We are a leading integrated wireless solutions provider who designs, sells, supports, and installs communications systems in the Greater Philadelphia area, including Bucks County, Montgomery County, Delaware County, and Chester County, PA; as well as Gloucester and Camden County, NJ; and New Castle County, DE.

Keep reading to learn more about BDAs, DAS, and how they work.

Why BDA and DAS Systems Are Essential

In buildings with thick walls made of concrete or steel, wireless communications like cell phones and radios are often unable to reach their destination. In addition, areas that host very large populations, like football stadiums, may not have the signal strength to accommodate so many cell phone users at once.

BDA/DAS solutions guarantee signal connections. They are useful for both commercial and private use, as well as public safety.

Consumer and Commercial Applications

Since they help improve in-building wireless signals, BDA/DAS technologies help employees stay in touch with each other from anywhere in a building. That way, colleagues can report issues more effectively and let each other know which tasks need to be completed, increasing productivity in the process.

Consumer and commercial signal-boosting systems are commonly used to improve wireless cell phone signals over long distances and in large crowds. Examples of consumer and commercial BDA/DAS systems include those found in shopping malls, high-rise hotels, and sports stadiums.

Public Safety Applications

Wireless cell reception is important for businesses and customers, but strong and reliable wireless communications are also essential in emergency situations. When every second counts, first responders need to be able to communicate with each other.

Many enterprises are legally required to install and maintain public safety BDA/DAS systems. Public safety signal boosters usually enhance wireless radio communications, so first responders can communicate with each other from inside and outside a building.

Metropolitan Communications is here to walk you through how BDA/DAS solutions work and how they can help you, whether you need more in-building coverage for business, public safety, or both.

How Do BDA & DAS Systems Work?

When a building has poor in-house communications signals, it is possible to fix the issue by capturing a wireless signal from outside and then re-distributing it inside with more signal strength.

A Distributed Antenna System (DAS) is used to re-distribute the signal, and Bi-Directional Amplifiers (BDAs) enhance signals in every part of a building. Although they are different, they work together as in-building signal boosters.

At a Glance: BDA vs DAS



What It Is

Specialized antenna

Signal distribution system

What It Does

Extends coverage

Extends coverage, enhances capacity

When it comes to losing an in-building signal, there are two root causes: problems with coverage and problems with capacity.

In areas where wireless signals often have trouble reaching, like basements and stairwells, you can experience issues with coverage. When in-building coverage is a problem, BDA antennas can help extend a signal, whether that is a cell signal, radio signal, or some other kind of wireless connection.

Issues with capacity occur when the signal strength cannot support all the users. At a sold-out football game, for instance, thousands of people using their cell phones at once can overwhelm nearby cell towers. This issue often requires a more specialized DAS to enhance signal capacity for everyone in attendance.

The Key Components of Signal Boosters

Although these types of equipment are customizable depending on the signals that need to be boosted, generally, in-building signal booster solutions include three key components:

  1. A donor antenna: This is mounted on the exterior of the building to capture the wireless signal from the outside and feed it into the building.
  2. A Distributed Antenna System (DAS): This is a group of antennas placed throughout a structure to disseminate the captured signal.
  3. Bi-Directional Amplifiers (BDAs): These are a type of signal-boosting antenna that work within a DAS. They extend two-way radio coverage into difficult-to-reach areas, such as stairwells, underground hallways, tunnels, parking garages, and other challenging zones.

As you can see, BDA and DAS technologies often work hand in hand, but there are differences in how they operate to increase in-building signal coverage and capacity.

The experts at Metropolitan Communications can inspect your enterprise, discern problem areas, and craft a custom solution that works for you. We want to ensure all communications come through loud and clear, no matter the circumstance!

Who Benefits from BDA/DAS Solutions?

BDA/DAS for Your Business

Since BDA/DAS solutions improve wireless communications, almost any industry benefits from them. Some of the industries that Metropolitan Communications has assisted include:

Essentially, almost any industry that benefits from guaranteed in-house wireless communications can benefit greatly from these technologies.

Since every industry is unique, BDA and DAS solutions are unique too. Keep reading to learn more about the practical applications of each and how Metropolitan Communications can help your enterprise.

About BDAs: Bi-Directional Amplifiers

As an important part of a Distributed Antenna System, Bi-Directional Amplifiers extend coverage into hard-to-reach areas. Essentially, a BDA will pick up a signal from a transmitting antenna, strengthen the signal, and extend it to wherever you need it.

BDAs are signal boosters that sustain wireless communications throughout a facility. BDAs have many practical applications, including connectivity for cell phones, public safety communications, radios, and Wi-Fi signals.

However, a cell signal-boosting BDA will not increase two-way radio coverage and vice-versa, so it is best to install each as a separate system, if needed. Some enterprises employ both cell-specific and radio-specific BDAs.

The convenience of this connection-amplifying solution means that you can begin construction in an old building or address a problem in a remote area without worrying about your portable radio losing its signal.

With BDAs in place, coworkers can get in touch with each other from wherever they are—meaning they can focus more on the job at hand and worry less about the reduced efficiency that comes with connectivity issues.

About DAS: Distributed Antenna Systems

A DAS is a more general term for any communications solution that ensures in-building coverage and capacity through the use of in-house antennas. There are a few different types of DAS solutions, and the two main ones are passive DAS and active DAS.

Passive DAS

Passive DAS systems work by receiving a signal from outside, bringing it into a building, and distributing that same signal via coaxial cables to amplifiers that live throughout the building. Since a DAS involves amplifiers, a passive DAS often employs BDAs.

With many buildings, this is enough to meet legal requirements and ensure that emergency personnel will be able to reach each other in case of an emergency.

However, signals often degrade over very long distances, like from the top floor of a hotel to the main lobby. For this reason, a passive DAS system works best in buildings that are under 100,000 square feet.

Active DAS

Active DAS solutions can help in buildings that are very large, like airports, convention centers, and sports stadiums. This is because when signals travel long distances, they begin to degrade.

Active DAS solutions are also useful for areas that host very large populations at once, like sold-out concert venues. When crowds gather in high concentrations, the multitude of cell phones can overwhelm the capacity of nearby cell towers.

A passive DAS solution simply passes a received signal throughout a building via antennas placed on every floor. An active DAS is different because it first converts the signal from a radio or cell frequency into an optic frequency.

After conversion, that signal is transported via fiber optic cables that connect to antennas placed throughout the building. This maintains the integrity of the original signal while increasing coverage and capacity for all the people in the area.

BDAs still prove useful in active DAS solutions since they extend this coverage into all areas of a structure, even if that signal has been converted in some way.

BDA/DAS for Public Safety

Why They Are Necessary

Thick concrete and metal can prevent signals from getting into your building, which makes conducting business difficult for both coworkers and clients.

In addition, not only do in-house communications solutions make good business sense, but they are also often required by different local and federal statutes for public safety reasons. After all, in an emergency, first responders need guaranteed clear communication throughout all areas of a building. For this reason, there are several legal regulations that require facilities to have guaranteed communication with emergency personnel.

In the same way that BDA and DAS solutions can enhance both coverage and capacity, legal requirements address both those root causes of wireless issues as well.

Legal Codes that Affect Your BDA/DAS Solutions: NFPA and IFC

When it comes to ensuring coverage, two of the most important requirements are put in place by the National Fire Protection Association (NFPA) and the International Fire Code (IFC). Some of these codes include:

  • NFPA 72 Chapter 24: Requires 90 percent of in-building coverage, as well as 99 percent coverage for critical areas, such as elevator lobbies, exit stairs and passageways, and fire pump rooms.
  • IFC-510: Requires 95 percent in-building wireless signal coverage with a minimum signal strength of -95 dB.

Not only must a BDA/DAS solution provide coverage in all areas of a building, but that coverage must be able to function under extreme conditions, like high heat and high humidity. They must also have backup batteries that last up to 12 hours, and sometimes even longer.

Legal Codes that Affect Your BDA/DAS Solutions: FCC

Another organization that regulates and enforces wireless communications standards is the FCC, or the Federal Communications Commission. Their regulations on communications traffic includes different kinds of wireless signals. They oversee many industries, and part of their role is to act in the interest of public safety by keeping certain airwaves free of clutter, so they have enough capacity for first responders.

This is outlined in the FCC’s Network Protection Standard, which is a “series of technical precautions that minimize the chances of signal boosters interfering with wireless networks.” When your BDA/DAS solutions operate on the proper channels, they make sure that nothing gets in the way of emergency responders.

More specifically, emergency responders operate on protected bandwidths, usually within the 600 MHz to 900 MHz range. Your signal-boosting system must be able to support these channels, and your enterprise must keep these channels clear.

Legal Codes that Affect Your BDA/DAS Solutions: FirstNet

Legal requirements evolve all the time. One example is the relatively recent creation of the First Responder Network Authority, or FirstNet, in 2012. This government organization aims to create and employ a nationwide wireless network for first responders.

Local ordinances often have regionally specific communications standards. Creating a nationwide standard will help first responders work more effectively in emergencies that affect many regions—like when a hurricane hits several states on the East Coast.

Keeping track of all these legal requirements can be challenging. Luckily, Metropolitan Communications is here to help make sure that all the equipment we install is up to code. This way, there’s no risk of facing heavy penalties. More importantly, there’s more assurance that if there is ever an emergency situation, everyone can be safer.

How Our BDA/DAS Solutions Can Help You

At Metropolitan Communications, our expert technicians have over 90 combined years of experience serving the Greater Philadelphia area. Before installing a custom BDA/DAS solution for you, we will perform an on-site survey. This survey will assess signal strength throughout the building and determine the causes of any poor signals.

From there, we can determine the best locations for donor antennas, in-building BDAs, and the type of DAS required. Since every solution is unique, our plans are too. We partner with major telecommunications corporations, like Motorola, Cisco, 3M, and more to bring you the latest and most advanced technology.

Our installation team is seasoned in installing all different types of equipment, including:

  • Antenna systems
  • Base stations
  • Repeaters
  • In-building amplification systems
  • Radio equipment
  • Emergency lighting
  • Mobile data terminals
  • Headset and intercom systems
  • In-vehicle cameras
  • Digital recording systems
  • Management information systems
  • Call-routing
  • Records management

Once your inspection and installation are complete, we are still here for you. In fact, we offer 24/7 support for all your needs, along with our data management systems.

Case Studies

Don’t just take our word for it—see how we have helped others in the area.


Nothing is more important than our children’s safety. Safety can be challenging in many schools, where concentrated populations and thick concrete walls can negatively affect signal capacity and coverage. That’s why Metropolitan Communications partnered with public safety officials and school district administrators in Southeastern PA to improve signal strength in schools.

Our experts reviewed, designed, and installed in-building NFPA (National Fire Protection Association) compliant solutions. After implementing their new signal-boosting solution, communications signals now reach previously hard-to-cover areas. According to local law enforcement, the results are “very positive.”


Our expert teams recently created a custom BDA solution for a local healthcare system to improve patient care and security.

In addition to being tested and approved by local first responders, the system also helped the healthcare facility by implementing a web-based notification system. This system provides email, text, or voice notifications in the event of a system issue. With this helpful automation in place, healthcare providers can spend more attention on patient care and worry less about communication problems in the event of an emergency.

Reach out to Metropolitan Communications Today!

No matter what, we can ensure that all our BDA/DAS solutions will be code-compliant, expertly installed, and consistently tested. We are ready to serve the Greater Philadelphia area, including Bucks County, Montgomery County, Delaware County, and Chester County, PA; Gloucester and Camden County, NJ; and New Castle County, DE.

Whether you work in public safety, education, healthcare, or another vital industry, our team is ready to partner with yours. To learn more about how we can help you keep your wireless communications efficient and compliant, reach out for a consultation and a quote today!