Why Every New Construction Building Should Have a Public Safety DAS

When an emergency occurs, reaction time and effective communication are vital. However, what happens if those inside a building do not have enough cellular coverage to call 911? Additionally, what if first responders cannot communicate via two-way radios once they enter a building? Without reliable in-building communications systems, emergency situations can escalate, putting those inside at a higher risk. 

When firefighters enter a high-rise building, point-to-point communications between those on scene and on the ground can become severed. This is a result of dense structural materials such as steel and concrete, which prevent or limit radio frequencies (RF).

Solutions exist to improve public safety communications and cellular coverage. Distributed antenna systems (DAS)— specifically public safety DAS—can support Land Mobile Radio (LMR) as well as the multiple frequency bands used by first responders, such as VHF/UHF and 700/800MHz. Additionally, cellular DAS solutions enhance the multiple LTE frequencies used by Verizon, AT&T, T-Mobile and Sprint.

With fire and building codes for public safety communications becoming more prevalent, property owners and building managers must stay up-to-date on necessary requirements. Most notably, the International Fire Code (IFC) now mandates a minimum of 95 percent general building coverage for public safety. The National Fire Protection Association (NFPA) requires 90 percent general building coverage as well as 99 percent coverage in all critical areas.

1. System Coverage

When mapping out your public safety DAS coverage, critical areas can include control rooms, pump rooms, stairwells, lower exit stairs, exit passageways, elevator lobbies and standpipe cabinet locations. As previously mentioned, the IFC mandates a minimum of 95 percent general building coverage, while the NFPA mandates 90% general coverage and 99 percent critical area coverage.  

2. Radio Coverage

Buildings and structures which cannot support the required level of radio coverage shall be equipped with a radiating cable system, a DAS with Federal Communications Commission (FCC)-certified signal boosters, or other approved system to achieve required radio coverage.

3. New Construction Properties

All new construction buildings shall have approved radio coverage for emergency responders based upon existing coverage levels of the public safety communication systems. This does not require improvements to existing systems.

4. Emergency Back-Up

In an emergency situation such as a fire, a building will most likely lose its main power source; a secondary solution will be required. The NFPA mandates 12 hours of emergency power battery back-up, while the IFC requires 24 hours. If Fiber-DAS is used, an optical-to-RF converter rack might be required to ensure uninterrupted service. 

5. System Monitoring

The NFPA Annex O requires an automatic monitoring system with a dedicated panel within the building emergency command center. The system must signal an alarm during an antenna malfunction or signal booster failure. A separate alarm for oscillating amplifiers is desirable. Power supply systems must—at a minimum—signal an alarm when AC power is lost, when the battery charger fails and when the battery has a low charge (defined as 70 percent capacity). 

6. Maintenance

The NFPA Annex O requires building owners implement a service contract for emergency repair. The response time shall be no less than two hours.

Two-way radios are a necessity for first responders putting their lives on the line every day. Similarly, the importance of reliable in-building cellular coverage continues to increase, especially with the adoption of LTE handset technology. DAS has proven to be a comprehensive solution for reliable in-building communication. With the ability to support both LMR/VHF/UHF and LTE frequencies, it will be continue to gain a foothold for emergency communications.

Airtower Networks provides customized solutions such as cellular, managed WiFi, private LTE, and more for seamless in-building connectivity, enhanced productivity, and a competitive bottom line. Connect with us today to commence your wireless networking journey!