Wireless connectivity rules just about everything today. Being connected is important for the rapid exchange of information, improving communication, and increasing productivity. To prepare a building or campus to provide extensive, uninterrupted wireless connectivity, the installation of a distributed antenna system (DAS) is required. DAS is simply a network of antennas that are installed to provide wireless connectivity for: Cell phone voice, cell phone data, network connectivity 802.11, first responder two-way radio systems, and real time location services (RTLS).

While the use of wireless data and voice communications in higher education and healthcare settings is creating new efficiencies and opportunities, DAS is making these gains possible by ensuring reliable transmission throughout the facilities.

DAS for Cellular Communications

The original purpose for DAS systems was to provide interior coverage of cellular frequencies into a building, thus allowing people inside of buildings to use their cell phones. However, DAS quickly became the solution for other internal building communications issues.


The original means of communication between police, fire, and other first responders were over dedicated frequencies, which were specific to police,fire, and others that did not allow interagency communications. It was desired that DAS systems carry first responder communications on the inside of buildings, but this was not possible, as each type of first responder had their own specific frequency ranges. To make matters worse, different cities and counties had entirely different frequencies. Due to this complex environment, it was not possible for a DAS system to carry all of these separate unique frequencies. The lack of ability for first responders to communicate amongst themselves (interoperability) and to communicate to crews outside of a building became apparent after 9/11, when firefighters were unable to communicate with each other, other teams, and with command and control.

The United States has since enacted interoperability requirements among police, fire, and other first responders legally requiring that they share common frequencies so that they could intercommunicate.  This opened the door for DAS systems to carry these specific frequencies inside of buildings, allowing all types of first responders to communicate amongst themselves.  

Ability to Communicate with Personnel Outside of the Building

Current codes in both IBC (International Building Code) and IFC (International Fire Code) require in-building DAS communication systems. Many times it is assumed that first responder communications work in all locations and areas of a building, and that first responders inside of a building can easily communicate with the outside. This is not the case if there is not a DAS system installed, as the buildings themselves act as a shield, limiting reception of outside signals, thus not allowing for internal/external communications. This is due, in part, to the building construction, interference within the building, age of the building, and proximity to a cellular tower. Additionally, communications in these buildings are inconsistent when traveling from area to area or even building to building, and many first responders don’t know where these problem spots are, or that they exist at all.  

In an increasingly security-conscious world, university and medical campuses face heightened concerns over disaster preparedness issues. In the wake of the Newtown, MA, shootings, the Boston Marathon bombing, and the Washington Navy Yard shootings, the ability of first responders to communicate, respond, and operate has assumed an even greater importance than was previously imagined. These concerns resulted in legislation requiring all new construction buildings to install DAS systems allowing the ability of any first responder to have clear communication with exterior command. There are many codes/standards that require first responder communications, two of which are the International Fire Code section 510 and the National Fire Protection Association Chapter 24. The code language contains specific requirements for DAS systems related to coverage, signal quality, survival, power backup, and license. Additionally a city’s local AHJ or fire marshall may have other specific requirements for DAS as adopted into their local building codes. Often, compliance to the codes and standards must be demonstrated during the building design phase to obtain construction plan approval and at the time of final inspection.

First responders must be able to utilize the campus DAS in the event of an emergency. Many times, without DAS communications located at a facility, first responder communications can be limited during crisis situations. It is for that reason that DAS for first responders needs to be considered during the planning of a new renovation or addition to a facility or campus. Building officials may not give occupancy permits until first responder communications are installed, and if they are not already in place, could considerably delay occupancy of a facility. When upgrading a single building on a campus, careful consideration needs to be given to how advanced communications in one facility affects the rest of the campus. First responders may need to operate –communicate–in many different locations, depending on the nature of the emergency.

Cost, of course, is a challenge on collegiate or healthcare campuses. Newly constructed buildings often include DAS while older buildings do not. This creates a gap in first responder communications as some portions of campus are connected and others are not. Administrators of large campus facilities are increasingly implementing policies and budgets that incorporate the addition of DAS within older buildings. Some federal grants have become available for facilities to update and/or install DAS deployments for first responder communication, and facility managers have gradually recognized the increased usefulness of DAS in facility management and building control, which can aid in some cost considerations.   

Designing a DAS system for either new construction or for an existing facility is a complex task that involves understanding the building construction, how the walls are reinforced, column placement, furniture, ceilings, interferences from equipment, signal strength and many other issues. For that reason, an expert in the design of DAS systems is strongly recommended. Technical challenges also exist when designing a DAS system as well.  Foremost is the frequency/protocol question and the ubiquity of the 802.11 Wi-Fi band. For instance the “802.11ac” standard was recently published and will eventually require that old DAS systems be upgraded. With first responder spectrums often being older and changing, a campus Wi-Fi system must be flexible, and have the ability to be configured to accommodate these new frequencies and protocols. Spatial requirements for additional equipment and the availability of inter-operative equipment will require consideration. 

What are other crucial design considerations when selecting a DAS system? Communication with first responders is essential (as obvious as that sounds) to determine whether those responders have established interoperability with police, fire, and other agencies. What frequency do local first responders operate at? Are there any wireless devices that can broadcast that frequency? Is add-on equipment or new equipment required? What are the future of 802.11 needs in the facility and what is coming down the pipe in the areas of broadband communications? What is the next step in cellular communications beyond 4G? These are just a few of the questions that need to be asked when incorporating a DAS into a building or campus.

Wireless Networks for Public and Private Use

As DAS becomes more popular, bandwidth is becoming limited. In many cases, two networks are being installed — one for public use and one for private use. 

Existing 3G networks present some difficulties. 3G devices can operate over a 4G network but the reverse is not true. Older DAS systems amplify and transmit 3G, but do not have the capability for 4G. In general, campuses or facilities need to upgrade to 4G for carriers of LTE. The caveat is that 4G will not be the last generation of wireless protocols and the upgrade to 4G can be costly. These factors have led some universities and healthcare facilities to view their network as a revenue source to offset the cost. The ability to sell content over Wi-Fi — inside theatres, stadiums, and other public venues–is gaining traction.  The attraction of watching replays, viewing player stats, or watching interviews on smartphones during a collegiate game offers a new revenue stream.

Wireless Communication for Converged Systems

Though DAS was originally developed for cellular phones, it now has the ability to integrate multiple wireless systems into one. In hospitals, a wireless revolution is being facilitated by DAS capability. As an example, an emergency room can now obtain critical patient data prior to the helicopter landing. DAS can now provide the structures and bandwidth of extremely fast and highly secure throughput, allowing access to portable systems in considerably less time.

The medical field is transitioning to the use of various wireless systems also because they facilitate using rooms for multiple purposes, and managing different types of medical devices remotely. Perhaps the biggest benefit to having a wireless network is that it allows providers to deploy technology at the bedside, as part of normal health care workflow. Providers can use smartphones to access clinical data and biomedical devices can record and manage patient information. Some researchers have predicted that millions of patients will be monitored with a wireless medical device in the near future.

While hospitals will still rely on hard-cabled ethernet systems for critical and bandwidth-intensive systems, wireless connectivity offers an additional level of communications that could not be offered because of a lack of a hard wired connection in all areas. For instance, wireless systems provide connectivity to portable devices allowing a hospital to know the locations and operation of every device within the system. Devices can furthermore communicate with other devices in a room.  Patient beds are becoming wireless, allowing communication of information while a patient is being moved to another location. The patient’s location, telephone, and other critical information will remain in operation while the patient is being relocated. 

While improving the patient experience, as wireless connectivity will do, and providing benefit to the patients, visitors, and the hospital staff, the initial cost is the main obstacle to implementing wireless systems in healthcare facilities. It is widely believed that these costs will be offset through insurance coverage, which will be keyed to patient satisfaction in the near future. It is more likely that hospitals that develop smartphone apps, for example, to guide the patient and family through every step and procedure from admission through discharge, will receive positive marks on satisfaction surveys, which in turn will improve a hospital’s overall rating.

Robotic devices, such as tugs that deliver towels and pharmaceuticals, will also be integrated with wireless DAS. Other, as yet unrealized, robotic devices may provide services more accurately, promptly and less costly than humans or stand-alone devices. 

Facility management will likewise be revolutionized as DAS allows building engineers and maintenance staff the ability to monitor and adjust heating, cooling, lighting, and power from any point within a large complex. 

RTLS (Real Time Location Services) can be integrated into DAS systems to provide location-based services. Even relatively simple tasks will be made more efficient; finding an AV cart or an available wheelchair for patient discharge will be instantaneous when it can be located via RTLS. Additionally, patients who have a tendency to wander can be tracked and infants can be instantly located.

Approaching Change

The worlds of higher education and healthcare are approaching a fundamental change via wireless communication.  The advent of DAS is facilitating a new, interconnected campus that will allow students and faculty, patients and medical professionals, first responders as well as facility managers, greater ability to monitor and control the environments where they live, study, work and heal.  Are you ready?   

About the Author

Jim Otte is a Senior Designer at SSOE Group (, a global engineering, procurement, and construction management firm. He holds several certifications and is the writer of several patents for new communication methods and data distribution. Jim has over 25 years’ experience and specializes in the engineering and design of complex data, fire, security, sound, and telecommunications networks. In addition he has expertise in commissioning, threat analysis, project and contract management, and quality control. Jim Otte can be reached at