The Definitive DAS Guide Philadelphia PA

DAS Definitive Guide

Your newly constructed hospital is made of the strongest, most durable materials. It has advanced tech and is guaranteed to help serve your community. However, when the fire marshal comes to inspect the structure, there’s bad news: It fails its safety inspection due to poor signal strength.

Buildings with thick walls or high populations, such as convention centers or stadiums, often do not have reliable radio or cell signals. On a day-to-day basis, unreliable network connectivity makes it more difficult for coworkers to communicate. Even more crucially, in emergencies, technical problems that cause breakdowns in communications can prevent first responders from administering the help people need.

Connectivity problems affect many kinds of large structures, which includes hospitals in Bucks County, PA, as well as sports stadiums and convention centers in Philadelphia, PA, airports in New Castle County, DE, and more. It also affects areas with a concentrated population, like at sold-out concerts in Camden County, NJ.

Luckily, Metropolitan Communications is here to help those living in the Greater Philadelphia area. With Distributed Antenna System (DAS) solutions, you can ensure strong, reliable in-building signals. Read on to learn what DAS solutions are, how they work, and how they can benefit you.

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What Is a DAS?

A DAS, or a Distributed Antenna System, is a connectivity solution that increases in-building communications signals for structures with poor in-house wireless signals, either for radio frequencies or cell signals.

A DAS captures a signal, feeds it inside, and distributes that signal throughout the building. It does not generate its own signal; rather, it enhances a pre-existing signal to maximize its efficiency.

In essence, there are typically three basic components to boosting in-building signal coverage:

  • A signal source, which is usually a donor antenna placed on the roof of a structure to capture wireless signals from outside, like radio frequencies and cell phone signals.
  • The distribution system, or Distributed Antenna System (DAS), is a group of antennas throughout the building. They receive input from the donor antenna and deliver those signals throughout the building. These systems often utilize Bi-Directional Amplifiers (BDAs), a type of antenna that works within a DAS to extend coverage into hard-to-reach areas, like stairwells and basements.

This guide will go over the technical specifics of how DAS solutions function, but first, let’s explore why they are necessary in the first place.

Who Benefits from DAS Solutions?

DAS solutions come in many forms for many different industries. Not only can this increased communication help employees and clients who come into the building every day, but it is also often a legal requirement, so first responders can act quickly in an emergency.

For these reasons, almost any industry can benefit from DAS solutions for increased connectivity. Some of the industries we service include:

When Is a DAS Necessary?

A DAS is beneficial for any building that has poor in-house communications signals.

When exploring DAS solutions, it is important to know that a poor signal can have different causes. These can be summarized as issues with coverage or capacity.

Coverage refers to making sure that all areas of a building receive a signal. For instance, wireless signals might not reach a basement or be able to penetrate thick concrete walls.

Capacity refers to making sure that all cell and radio users can utilize a signal. This includes locations that host very large populations at once, like convention centers during a concert or sports stadiums during a playoff game. In these situations, the multitude of cell signals can overload nearby cell towers.

In both cases, wireless communications signals suffer, but since the causes can be different, the solutions must be too. Fortunately, a custom DAS solution from Metropolitan Communications can solve both these issues.

DAS for Business Needs

For many businesses, dropped calls and unreliable service can translate into lost sales and decreased efficiency. If one of your prospective clients can’t rely on your business to stay on the line, they may simply go elsewhere.

On the business end, when coworkers cannot reliably communicate with each other, it decreases efficiency—and the bottom line. From a loss prevention perspective, for instance, security guards at a shopping mall need to be able to get in touch with each other at all times to prevent theft or damage to the property.

DAS for Public Safety Requirements

However, in many cases, a DAS solution is more than just smart business sense; it’s also often legally required. At the state and federal level, different organizations require that local emergency responders can communicate without hindrance. After all, when every second counts, staying in touch with those who can provide help is crucial.

Complying with wireless signal codes improves personal safety, minimizes the risk of property damage, and reduces the possibility of legal liability.

There are a few regulatory bodies that require guaranteed communications, including:

  • National Fire Protection Association (NFPA): NFPA 72 Chapter 24 code requires 90 percent in-building two-way radio signal coverage, which jumps to 99 percent for critical areas like fire pump rooms, exit stairs and passageways, and elevator lobbies.
  • International Fire Code (IFC): IFC-510 code requires 95 percent in-building wireless signal coverage with a minimum signal strength of -95 dB.
  • Federal Communications Commission (FCC): Part 90 of FCC13-21 regulations describe requirements for signal boosters for public safety and private Land Mobile Radio (LMR) service operations. In addition, the FCC bars public use of radio frequencies in the 600 MHz service band and on the 700 MHz band. These frequencies are reserved for public-safety networks and licensed commercial use only.

Legal requirements cover more than just bandwidth and coverage, though. There are other aspects of your DAS solution that must pass compliance inspections, like the durability of the equipment itself. Antennas in a DAS must have guaranteed battery backup power, for instance. They must also be able to withstand extreme heat and humidity.

Regulations are always evolving too. In 2012, Congress approved the creation of the First Responder Network Authority, or FirstNet. This government organization aims to build and operate a nationwide “fast lane” broadband network for first responders. Streamlining communications channels will aid in emergency situations that affect several localities, like hurricanes that travel up the East Coast.

As FirstNet rolls out in each state, DAS solutions will have to ensure connectivity to FirstNet’s frequencies as well. These frequencies are within the 600 and 700 MHz service bands that the FCC has delegated to public safety use.

These legal requirements can be a lot to keep track of. Luckily, we employ technicians at Metropolitan Communications who are FCC-certified. With over 90 years of combined experience, they can inspect your building and create a compliant, custom plan for you.

How DAS Solutions Work: Types of Signal Sources

As mentioned previously, knowing what kind of connectivity problem is present will determine what kind of signal source is required for a DAS.

A DAS does not generate its own signal; it re-distributes an existing one. There are three main types of signal sources: off-air (repeaters), on-site (BTS), and small cell.

  • To solve the problem of reduced coverage, off-air signal sources are common. These are also sometimes called repeaters, and they utilize a donor antenna on the roof to capture and distribute cell signals throughout a building whose structure may be blocking signals from getting inside. It does not add extra capacity.
  • To solve the problem of reduced capacity, on-site signal sources account for large crowds that can overwhelm cell towers. These use Base Transceiver Stations (BTS) and often require a fiber connection that is specific to one cell carrier.
  • Small cell signal sources are newer technology that rely on venue-provided internet connections to generate high-quality wireless signals inside a building. With this, an enterprise can expand both coverage and capacity, although it works best with smaller populations.

It is also possible to mix and match these signal sources to create the most effective DAS solution.

How DAS Solutions Work: Types of Distribution Methods

Choosing a type (or a few types) of a signal source is the first step in crafting a DAS solution. From there, it is necessary to determine what kind of in-building distribution methods will work best for your needs. There are four main types: passive, active, hybrid, and digital.

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.

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 one end of a football stadium to another. 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 and lose their efficacy.

Instead of simply passing a received signal throughout a building via antennas placed on every floor, like with a passive DAS solution, an active DAS will first convert the signal from a radio or cell frequency into an optic frequency. Then, the signal will be transported via fiber optic cables that connect to antennas placed throughout the building, maintaining the integrity of the original signal.

Hybrid DAS

A hybrid DAS is just what it sounds like: a blend of passive and active distribution technologies. A passive DAS will not convert a signal at all, and an active DAS combines optic technology with its antennas. A hybrid DAS utilizes one converter and then relies on passive coaxial cables to distribute the signal throughout a building.

Converting a signal in one location still upholds the integrity of the signal, but relying on a more passive distribution from that point can be a more cost-effective option, depending on your needs.

Digital DAS

The very latest development in DAS technology is the Common Public Radio Interface (CPRI). Traditional active DAS solutions convert signals from radio frequency (RF) to optic using fiber optic cables. The CPRI takes the RF signal and digitizes it before sending it to antennas. Converting the signal before distribution instead of after makes it possible for signals to travel wirelessly from your Base Transceiver Station (BTS) to distributed antennas. A digital DAS removes the need for cable installation.

This technology is still new and evolving, but it is useful in very large and crowded areas. In fact, it is being installed in all five terminals of the Dallas Fort Worth airport.

Creating a Plan that Works for You

So far, this guide has covered the root causes of signal weakness, the kinds of donor antennas that feed signals in-building distributors, and the different types of DAS setups. With these options, Metropolitan Communications can create a custom solution tailored to your business’s needs. In the same way that it is possible to mix and match donor antenna solutions, it is also possible to mix and match other components as well.

  • A Passive, Off-Air DAS might work for you if you need coverage throughout a large building with thick construction materials, like a surgical center.
  • A Passive, Small-Cell-fed DAS helps if you need coverage and capacity for areas up to 700,000 square feet where an internet connection is reliable.
  • An Off-Air Hybrid DAS could be a solution if you need to increase coverage over a very large area, but have a sparse population, like in a specialized manufacturing facility.
  • A BTS-fed Active DAS might work for you if you need it all—to increase coverage and capacity over a large, crowded area. Guarantee a connection for everyone in a packed convention center or sold-out sports games.

Type of DAS



Area Size

Passive, Off-Air


Not required


Passive, Small-Cell



Large, with Strong Internet Connection

Off-Air Hybrid


Not required

Very Large

BTS-fed Active



Very Large, no Strong Internet Connection

What Are BDAs, and How Do They Work with DAS?

When reading about DAS solutions, it’s possible you’ve come across the term BDA. BDAs, or Bi-Directional Amplifiers, often work in conjunction with DAS solutions. DAS solutions require antennas to distribute signals, and BDAs are a type of antenna that make DAS work.

Specifically, BDAs are employed to guarantee a signal in hard-to-reach areas of a building, like stairwells, elevators, and basements. When a DAS solution employs BDAs, everyone who uses the building for day-to-day operations, like security personnel, are guaranteed to be able to get in touch with their coworkers.

As an important part of a Distributed Antenna System, BDAs pick up wireless signals in areas with little to no coverage. From cellular and Wi-Fi connections to public safety connectivity requirements, this wireless integration solution meets the needs of a variety of different industries.

In addition, and often most importantly, employing BDAs means that firefighters, law enforcement, and other emergency personnel will not lose touch with their teams in emergency situations.

Case Studies: How Metropolitan Communications Helps Locals


Metropolitan Communications works with businesses in the Southeastern Pennsylvania area to ensure effective communications when it matters most. For instance, our expert teams recently reviewed, designed, and installed a BDA solution for a local healthcare system to solve communications challenges. The goal was to improve patient care, as well as security.

Not only was the system tested and approved by local first responders, but we also helped the business utilize a web-based system that provides email, text, or voice notifications in the event of a system issue. Now, these healthcare providers have the support they need to ensure the safety and security of those who depend on their services.


Many schools are very large facilities that host events, but are not always able to provide reliable in-building coverage. Public safety officials and school district administrators in Southeastern PA recently looked to improve reliability and interoperability between users on the same frequency spectrum in their schools.

Our experts reviewed, designed, and installed in-building, NFPA (National Fire Protection Association) compliant solutions for school districts. According to local law enforcement, the results are “very positive,” with communications signals strong and reliable in previously hard-to-cover areas.

In our ever-changing society, Metropolitan Communications is an authority on forward-thinking solutions. Reach out today to see how we can improve your in-building communication signals, and in turn, improve your productivity and emergency preparedness.

Install DAS Solutions in Your Workplace with Metropolitan Communications Around Philadelphia, PA

Our expert technicians have all the tools needed to identify the need for a DAS and the expertise to install them all over the Greater Philadelphia area, including Bucks County, Montgomery County, Delaware County, and Chester County, PA. We also service regions of New Jersey, including Gloucester and Camden County, as well as New Castle County, Delaware.

We partner with major brands like Motorola, Zetron, Kenwood, and more to bring two-way radios, Bi-Directional Amplifiers, and other wireless communications solutions to you. Plus, our 24-hour service means that whenever you need us, we’re here for you.

Contact us today for more information, to request a quote, or to take a look at our wide variety of wireless communications solutions.