Among the tragedies of the September 11, 2001, terrorist attacks in New York City were those caused by an almost complete communications meltdown among emergency workers at the scene. While police got the order to evacuate from the World Trade Center’s burning north tower, for instance, firefighters didn’t-and many of them were still inside the tower when it finally collapsed. And that was only one of a number of communication failures that directly or indirectly cost lives. The inability to track personnel, to get pictures from TV news reports or helicopters showing the condition of the towers, and even incompatible radios that couldn’t talk to each other all contributed to the disaster.
Help in improving communications among emergency workers, however, is on the way. Wireless networking technologies being tested and deployed in U.S. communities could solve at least part of the problem. The new networks are providing police and firefighters a way to pass vital data such as video, maps, and photos among themselves quickly and easily. Voice communications may take longer to modernize and integrate, but observers point to progress in an area called “software radio” that will let emergency workers from different agencies talk with each other more easily.
Wireless laptops that display information such as drivers’ records have been a common feature in police cars for at least a decade. But they have typically been connected via cellular networks that deliver data at dial-up-connection speeds or even slower, meaning that they are generally limited to receiving text. But now, faster data networks for police cars, fire trucks, and ambulances are giving officials access to more kinds of data and allowing them to share it with each other. Starting in May, for instance, fire, police, and ambulance workers in Garland, TX, will be able to use their existing laptops to send and receive mug shots, fingerprints, live video, medical data, and even floor plans at DSL-like speeds-while racing along at highway speeds.
Garland’s system, developed by partners NexGen City of Richardson, TX, and MeshNetworks of Maitland, FL, uses a technology called mesh networking, in which the laptops instantly become nodes in a network simply by being on and within range of each other. Each laptop routes data to others nearby, so that data crosses the network by hopping along the most efficient path from one laptop to the next. By avoiding the tower-based, hub-and-spoke configuration typical in cellular networks, mesh networks can work around dead spots created by interference from buildings.
They are also self-healing, meaning they simply reconfigure themselves if any node is lost, says Rick Rotondo, MeshNetworks’ vice president of technical marketing. Consequently, no single node is indispensable, as a central tower is in a cell network. Mesh networks can also route data around bottlenecks to ensure fast transmission, and their range of coverage can easily be extended by attaching additional routers to traffic lights and lamp posts. The Garland system offers coverage across more than 150 square kilometers.
“To the guy on the street, [high-speed data in vehicles] is going to make a huge difference,” says Joe Hanna, a consultant in Dallas, TX, and a past president of the Association of Public Safety Communications Officials. In addition to Garland, MeshNetworks is installing its system in Medford, OR, and has several trials and commercial deployments under way with other cities in the United States, Europe, and Asia.
While sharing data among emergency responders is relatively simple, sharing voice communications is actually far more difficult, since different radios are hardwired to transmit and receive at specific frequencies using different communications protocols. One solution could be software radio, in which radios store programs that automatically switch frequencies and communications protocols as needed to communicate with other devices. Cambridge, MA, startup Vanu, for example, is demonstrating a Compaq iPAQ handheld computer equipped with radio software that police or fire officials can use to communicate directly with different public-safety radios on any frequency between 100 and 500 megahertz. Meanwhile, Thales Communications in Clarksburg, MD, will target state and local agencies with a smaller, lighter version of a software radio it now sells to the military. “I think software radio will be the ultimate solution to the interoperability problem,” says John Powell, a public-safety technology consultant to the U.S. Departments of Homeland Security and Justice.
It’s unclear how readily software radio or mesh networking will be adopted by fire and police departments across the country, which often struggle simply to keep their existing equipment from becoming obsolete. And beyond the technical and financial challenges, there is still the hurdle of overcoming traditions. Different agencies have historically resisted cooperating with each other when buying radios, although that is beginning to change, says Craig Jorgensen, who is working with the Association of Public Safety Communications Officials and other groups to develop a standard for radios for emergency workers. Working together, Powell says, public agencies may help push to market technologies that could prevent a tragic communications crash like the one that occurred on September 11. But in the end, finding a solution will depend on how well the different officials listen to each other.
Connecting First Responders
|MeshNetworks (Maitland, FL)||Hardware for wireless broadband mesh networks|
|NexGen City (Richardson, TX)||Hardware for wireless broadband mesh networks|
|PacketHop (Belmont, CA)||Software-based mobile mesh networks for interoperable data communications|
|Raytheon JPS Communications (Raleigh, NC)||Patching devices to allow different radios and telephones to talk to each other|
|Thales Communications (Clarksburg, MD)||Software radio|
|Tropos Networks (San Mateo, CA)||Mesh networks using Wi-Fi wireless broadband|
|Vanu (Cambridge, MA)||Software radio|