An emergency responder radio coverage system (ERCES) is an in-building system that carries the two-way radio signals used by firefighters, police and emergency medical services through a building, so responders can talk to each other and their dispatch center from inside. It usually combines a donor antenna, one or more bi-directional amplifiers (BDAs), and a network of indoor antennas and cabling, built to stay working during a fire or power failure. In the US, the need for an ERCES is set by locally adopted fire and building codes, and the local fire authority decides whether a building needs one and whether it passes. It is also called a public safety DAS.
At a glance
- An ERCES carries public safety radio, not commercial cellular service.
- Whether a building needs one depends on local code, building size and construction, and a radio coverage test; rules vary by jurisdiction.
- Systems typically include a donor antenna, bi-directional amplifiers, indoor antennas, backup power and fault monitoring.
- The local fire authority and the radio system’s operator usually must approve the design and accept the finished system.
- Ongoing testing and maintenance are commonly required after the system is accepted.
What problem it solves
Concrete, steel, below-grade floors and energy-efficient glass block radio signals. In an emergency, a firefighter on an upper floor or in a basement may be unable to reach the incident commander, which is a direct life-safety risk. Many jurisdictions therefore require new buildings, and some renovated or expanded buildings, to show adequate in-building coverage for public safety radio before they can be occupied.
When a building fails that coverage test, an ERCES is the usual fix. For owners and tenants, the practical problems are a held-up certificate of occupancy, a failed inspection or a requirement discovered late in construction.
How it works
Assessment. A radio frequency survey or coverage test measures public safety signal strength across the building against the jurisdiction’s criteria. If coverage falls short, a system is designed to close the gaps.
Design and approval. The designer identifies the frequencies used by local agencies, places indoor antennas and specifies equipment. In the US, plans usually go to the local fire authority for review, and the agency that runs the radio system often must authorize the building to retransmit its signals.
Equipment. A donor antenna on the roof points at the public safety radio site. Bi-directional amplifiers boost signals in both directions, and coaxial or fiber cabling feeds antennas across floors, stairwells and other critical areas. Codes often call for protected cabling pathways, enclosures, battery or generator backup and alarm connections to the fire alarm system. Specific requirements depend on the adopted code.
Acceptance and upkeep. After installation, an acceptance test checks coverage and system operation. Many jurisdictions then require periodic retesting, monitoring and repair by qualified technicians.
Some buildings design an ERCES alongside a cellular distributed antenna system (DAS), sharing pathways while keeping the public safety equipment to its own standards. To scope in-building coverage, see our distributed antenna system solution page.
When it matters for buyers
- New construction and major renovations. Find out early whether a coverage test is required, because the result can affect occupancy timing.
- Tenant improvements. New walls or floors can change coverage in an existing building; check with the fire authority.
- Leasing a building. Ask the landlord whether the building has an ERCES, whether it passed its last test, and who pays for upkeep.
- Failed inspections. A failed annual or acceptance test can carry deadlines set by the authority.
Questions to ask vendors
- Which fire code and standards has our jurisdiction adopted, and what coverage criteria apply?
- Will you perform the coverage test, and are your technicians qualified as our jurisdiction requires?
- Who obtains approval from the fire authority and from the radio system operator?
- What backup power, monitoring and cable protection does the design include, and why?
- How does the system connect to our fire alarm panel?
- What testing and maintenance will be required after acceptance, and what will it cost each year?
- Can the design share pathways with a cellular DAS if we add one later?
How it differs from a cellular distributed antenna system
A cellular DAS brings commercial mobile service to phones and devices for the building’s occupants and is usually optional. An ERCES brings public safety radio to responders and, where code requires it, is a condition of occupancy. They can look alike on a floor plan, but they use different frequencies, are approved by different parties, and the public safety system usually faces stricter rules on backup power, monitoring and cabling. A cellular signal booster carries only commercial cell signal and generally does not meet public safety requirements. Requirements vary by jurisdiction, so confirm with the local authority before you design or buy.