Public Safety DAS- New Levels of Compliance

Public Safety DAS- New Levels of Compliance

Public Safety DAS – New Levels of Compliance

by Will Washburn
published 11.25.17

There is a lot of discussion recently regarding Public Safety Systems. A Public Safety DAS system is a RF based wireless communications system used by first responders such as police, fire, emergency services, disaster response agencies and homeland security. These systems are either analogue or digital, and operate on frequencies allocated by the FCC for communication between fixed base stations and mobile transceivers. The VHF and UHF elements of the spectrum, (45MHz, 150MHz, 220MHz, 400MHz, 500MHz) are analog radio systems and were primarily designed for voice communications. Some new Public Safety frequencies utilize digital technology and operate in bands like 700Mhz or 800Mhz. First responders require seamless communication to carry out their mission, including but not limited to in-building coverage. Bi-Directional Amplifiers (BDA) are utilized to propagate coverage within a structure that due to construction densities, may block RF signal. A Public Safety DAS is a distributed antenna system connected to a BDA to amplify a signal within the structure and allow transmit and receive signals to the base station. The internal array of antenna’s and BDA are connected to a donor antenna on the property that communicates to the transmitting base station antenna.

There are National, International and local codes that were modeled to bring standards to Public Safety Systems.  The National Fire Protection Association (NFPA) and International Code Council (ICC) have model codes issued by the National Fire Code, National Electrical Code and International Building Code, which are adopted and modified by local counties and cities. The nomenclatures of ordinances and codes vary by city; however, the common features are:

A minimum Signal limit

A minimum area of coverage

A reliability & installation standard

A monitoring and maintenance requirement

Provisions for compliance

The Authority Having Jurisdiction (AHJ), determines the code requirements and compliance of such. In many cases the AHJ is the Fire Department, and is the authority that insures compliance to the local code which is modeled around the National Code. In some jurisdictions, all cable is required to be run in 2 hour rated conduit where another jurisdiction only requires 24-hour battery back-up to all active network elements. Because all the compliance is on the local level, there has been a slow adoption rate and enforcement program. Some authorities have been quicker to implement policies than others, however most now have some program in place that has evolved over the years since the national codes were drafted.

Interoperability between frequencies and technologies has not existed until recently. On February 22, 2102, the Middle Class Tax Relief and Job Creation Act created Firstnet (First Responder Network Authority), in efforts to build and operate the first nationwide high speed broadband network dedicated to public safety communications using the 700Mhz spectrum. Firstnet will end a long history of interoperability and communications issues and is a blueprint for creating a nationwide network and providing wireless services to Public Safety agencies across the country. Congress has allocated up to $7 billion in funding for the construction of the network and will require each state to either create their own RAN and connect to Firstnet’s Core or opt-out and have Firstnet build their RAN. AT&T was awarded the sole vendor contract and the initiative is to be implemented by 2022.

In-building, Public Safety Systems will remain the responsibility of the building owner and compliance has been gradually stepped up in most jurisdictions. Many legacy buildings that are non-compliant are being tested to determine if a system is indeed required. If the building fails or certain areas fail, the AHJ may require the property to install a BDA system. The installation will cost the building owner anywhere from $.40 – $.95 per square foot, depending on the venue. If a building does not comply with the AHJ’s requests to have a BDA system installed, the authority can suspend the certificate of occupancy. For new construction, the AHJ will may not issue a certificate of occupancy, until the developer can prove that they have a compliant and fully functional BDA DAS system. Although many AHJ’s have been slow to implement enforcement policies,  3rd party consultants and education programs, have raised the bar on compliance.

Will Washburn, is the COO of Combined Operations for Digitechx Inc. a global provider of wireless services to the carrier and enterprise markets.


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