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How IP is improving public safety radio communications and interoperability

DENVER—In a bid to improve its overall communications with officers and to allow other agencies with incompatible radio systems to talk to them, the Denver Police do something different. They installed an IP-based software platform.

Specifically, the DPD opts to install M/A-COM’s NetworkFirst ™, which uses voice over IP for voice transmissions and a packet switch to allow incompatible radio systems to interconnect and communicate with DPD officers and dispatch. NetworkFirst achieves this by having each of the incompatible radio systems connect to a VoIP “gateway.” The software-driven gateway simply converts each audio transmission into IP packets, then routes the packets down the department’s private IP data network to a NetworkFirst Switching Center. The Switching Center then routes the IP packets to the correct radio system, where they are converted back into audio. The result is fast, efficient and practically invisible radio interoperability.

In Denver, the DPD adopted NetworkFirst after M/A-COM’s tests successfully connected it to 13 incompatible local, state, and federal radio systems. “With NetworkFirst, we now have real radio interoperability in 10 counties, including the city of Denver,” said Dana Hansen, the DPD’s manager of wireless systems. “Thanks to the nature of IP-based networking, our system has room to handle up to two million users, which is astronomical. Currently, we have less than 20,000 users on the system, so we have lots of room to grow.”

Meanwhile, in the Canadian province of Alberta, the Edmonton Police Service has turned to IP to radically improve its in-car data capabilities. Small wonder: The EPS’ original DataTAC network, although capable of operating in the 800 MHz radio band, could only achieve data rates up to 19.2 kbps. This is why “we decided to boost our data capacity by connecting our systems to the public EDGE (Enhanced Data GSM Environment) cellular broadband network and local Wi-Fi (802.11) hotspots,” said Randy Talbot, manager of the EPS’ telecommunications section.

To make this happen, the EPS installed Radio IP MTG™ with RadioRoam® connectionware from Radio IP Software. Capable of operating over EDGE and Wi-Fi networks, Radio IP MTG provides a mobile VPN to the EPS’ 250 patrol cars, plus “always on” wireless connectivity to all police department’s data networks. Meanwhile, the RadioRoam feature allows EPS patrol officers to seamlessly switch back and forth between the non-IP DataTAC and IP-based EDGE and Wi-Fi wireless networks; without breaking their logged-in sessions.

That’s not all: Radio IP MTG has allowed the EPS to connect its dispatch networks directly to its patrol cars, with in-vehicle GPS receivers telling dispatch where these cars are in real time. Add the ability of EPS patrol officers to download mugshots and detailed license information to their cruisers quickly and reliably, and IP technology has exponentially improved the department’s radio data communications.

Why IP Works

Clearly, IP technology is proving itself in public safety communications. Its adoption is allowing police departments like the DPD and EPS to substantially upgrade their radio communications and interoperability capabilities, without requiring a complete hardware rebuild or a forklift upgrade.

There are many reasons why IP is making a difference.

Without a doubt, the fundamental reason is that IP solutions are software-based, rather than hard-wired into physical equipment. This means that, as programs are revised and improved, these improvements can be deployed across existing police wireless networks. In contrast, legacy police communications are typically hardware-centric, with their proprietary functionality defined by their physical architecture and equipment.

This helps explain one reason why achieving radio interoperability is such a challenge for U.S public safety agencies: They are wedded to whatever proprietary non-IP radio system they bought years ago and cannot see a way out of this straitjacket except by buying a truckload of “open standard” P25 radios and base equipment. What many fail to see is that the answer lies in communications software, not hardware; and when it comes to a communications software standard, IP is king.

“Radio IP can port IP data over non-IP radio networks as well as IP radio networks,” said Shane Nolan, Radio IP’s product manager. “We can do this thanks to our server product. It’s designed to search through a department’s available networks, searching for the best connection to users. Not only does it dynamically reduce data rates to deal with older non-IP networks, but we have adapted Radio IP to compensate for the intrinsic characteristics of IP LAN traffic, including its tendency to have problems with wireless signal latency and the stop-and-start nature of wireless data communications due to signal dropout and users moving from one radio transmitter to another.”

The second reason, which has already been mentioned above, is interoperability. For public safety voice and data traffic, IP serves as a common linking language. As long as incompatible radio and data networks are all linked to something like a NetworkFirst gateway, which converts their signals to the same IP language, concerns about incompatibility are a thing of the past. For departments with budget constraints, this interoperability solution allows departments to keep using their current legacy, proprietary radio systems. Not having to do a complete equipment switch-out is not only cheaper for public safety agencies, but much easier to attain sooner using IP due to relative low cost. A third plus for IP and public safety communications is scalability. Unlike proprietary radio technologies, IP-based communications networks can easily be scaled up to serve many more users in local, regional, statewide, or even nationwide systems at minimal extra time and cost.

A fourth reason is that, by moving to IP, public safety agencies can take advantage of commercial-off-the-shelf IP technology; thus enjoying economies of scale not possible with legacy radio systems. “IP is the largest and best supported standard that there is,” said John Facella, M/A-COM’s public safety market director. “This means that there are multiple vendors out there selling proven technology at competitive prices. As well, by using conventional IP technology, public safety agencies can take advantage of Moore’s Law—increasing their capabilities over time while reducing their costs.”

Planning Considerations

This said, there are still some aspects of IP that must be carefully managed if it is to cover all public safety requirements.

The biggest issue is reliability: Unlike business networks, public safety IP networks must be robust, redundant, and designed to handle failures seamlessly. “Police, fire, and EMS communications are definitely ‘mission critical,’” Facella said. “If a corporate LAN goes down for an hour, it’s mainly a nuisance. But if a police IP system fails and knocks out the department’s 911 center, the result could be robberies in progress not responded to and calls for help unanswered. People could die. M/A-COM’s IP systems are designed to be survivable without single points of failure.”

The second concern is cultural: Most police, fire, and other public safety agencies are not accustomed to working with IP. For them, it’s a black box that runs their e-mail at the office and Web surfing at home. Bringing IP onto the front line of public safety communications makes them nervous.

In the same vein, many IT professionals are new to public safety; they lack the kind of training and field experience enjoyed by police, fire, and EMS officers. “This is why, when we looked at using Radio IP, we worked closely with DPD officers and their commanders to make sure that we were building a system that addressed their needs,” Hansen said. “It’s vitally important for public safety IT personnel to put their users’ needs first, and to keep them informed as to what’s happening.”

Conclusion: IP Belongs in Public Safety Communications

Even with the issues noted above, IP technology offers tremendous benefits to public safety communications and interoperability. “IP has really made a difference to our department,” Hansen said. “It’s an important tool in helping our officers communicate with us, each other, and other departments.”

James Careless is a freelance writer who specializes in first responder communications issues. He can be reached at

Published in Public Safety IT, Jan/Feb 2007

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