Leveraging Wi-Fi for Emergency Communications
As nations consider migrating emergency services communications from narrowband P25 or TETRA systems to national Public Safety Broadband Networks (PSBNs), agencies must consider the effectiveness of in-building coverage. New buildings are constructed with energy conservation in mind.
Buildings bounce sunshine heat away, and with it the cellular or narrowband radio signals from outside. The same can be said for citizen access to 9-1-1/999/112. Calling for help from a cell phone may be impossible. Old buildings in the middle of European cities frequently lack access to cellular services, as well. Zoning limitations on cell site construction and thick masonry walls can combine to create dead zones in the European city centers.
One solution is to add in-building coverage with robust and fault-tolerant distributed antenna systems. The U.S. has building code requirements for such capabilities in new construction. But getting ubiquitous in-building coverage extension is not practical for older buildings. The cost is high, and the political will is low.
A valuable adjunct can come from public or enterprise Wi-Fi deployed in large premises such as airports, hospitals, schools, hotels, and convention centers. While not perfect -- Wi-Fi is not in licensed and protected spectrum, and the premise equipment is not guaranteed to work during power failures -- the capability can dramatically extend access for visitors or arriving emergency services personnel.
The question of how to leverage public Wi-Fi appropriately for emergency calling, such as 9-1-1/999/112, or how to support incoming responders, has been an open one. Past Wireless Broadband Alliance (WBA) efforts to establish effective hotspot roaming support, with its PassPoint and OpenRoaming functionality, have hinted at the potential for seamless, automatic access to these networks in times of emergency.
Today, the WBA announced its vision for Wi-Fi in public safety (link with a press release and a suite of white paper reports that are a must-read for public safety communications agencies and national communications regulators.
Wi-Fi is not perfect, but it is nearly ubiquitous. The steps that WBA are taking will help more citizens and first responders benefit from access to emergency communications when building structures block access to macro network cellular signals.
Reports
Emergency Calling over Wi-Fi Networks Industry Framework (link)
Cellular Emergency Calling over OpenRoaming Wi-Fi Networks (link)
National Security & Emergency Preparedness (NS/EP) (link)