Putting MDCs on the beat: ‘Almost as important as their guns’

Expanding mobile communications to include CDPD gives police in three communities a resource to improve safety, efficiency and cooperation in real time

For decades, police agencies nationwide have depended on voice dispatch to maintain the lines of communication that are vital to doing their jobs. But, as communities and departments grow and the number of 9-1-1 calls escalates, officers are finding that voice frequencies do not answer all their needs.

This problem was evident in Philadelphia as early as 1994, when a congested voice system delayed response to the frantic 9-1-1 calls of several citizens who watched helplessly as a group of juveniles attacked young Eddie Polec with a baseball bat. Police officers didn’t arrive until 45 minutes after the first 9-1-1 call. By then, Polec was dead.

Deputy Commissioner Charles Brennan, of the Philadelphia Police Department, Scientific and Technological Division, said he believed officers were available to answer the call on time, but the overcrowded voice channels had made it impossible to get Polec the assistance he needed.

“There were probably units available, but we couldn’t get an assignment out because the radio was so clogged,” Brennan said. “When one officer is talking to dispatch, other officers and dispatchers can’t speak. It shuts them out. They have to sit and wait their turn.”

Wait times can be particularly severe in major metropolitan areas. In Philadelphia, one dispatcher routed 30 or 40 vehicles using only a single pipeline. And, with more than three million 9-1-1 calls and one million field checks per year, it was evident to this agency that its once reliable voice system was no longer sufficient. The Polec incident brought the problem to the forefront.

Congestion afflicts all markets Communications problems aren’t limited to metropolitan areas. System overloads have victimized smaller communities such as West Jordan, a suburb of Salt Lake City, and Altamonte Springs, FL, which lies just west of Orlando.

West Jordan’s police department is one of 53 agencies within the Wasatch District, which covers half the state of Utah. With the district’s system of two-way radio dispatch through the Valley Emergency Communications Center (VECC), each agency found it difficult to distribute critical information across jurisdictions.

“We had no common radio frequency to communicate with each other,” said Lt. Phil Bates. “We had no communication.”

This lack of communication gave fugitives an easier channel of escape once they crossed a department’s field of command.for vehicle and background checks.

“We’ve grown tremendously in population over the years, and there’s only so much room for growth with radio spectrums,” Bates said. “[Frequencies are] all issued out, so there’s no way to obtain any more. We needed to find a new system of communication.”

So did Altamonte Springs, which had gotten by for years with a single-channel, two-way radio. More than 40,000 residents make their homes in the city’s 9.5 square miles, and another 25,000 commute there each day to work or shop. But, with a limited number of dispatchers handling the 50,000 9-1-1 calls and numerous field requests, the police department outgrew its single frequency.

But that wasn’t all. The communications between officers and dispatchers were chaotic. Using the two-way radios, dispatchers would send the 9-1-1 calls to all officers in the field, giving them the chance to ask questions or to volunteer to take the call. Questions about addresses and case data caused severe delays, as officers asked dispatchers to repeat crucial information.

Likewise, non-emergency queries to the licensing database took nearly two minutes to complete because all the data were stored in one terminal. Furthermore, Altamonte Springs’ unsecured voice channel opened up officer’s communications to eavesdroppers, putting officers and victims at risk.

Getting backup from bits Each of these precincts, big and small, realized it had outgrown its voice dispatch system and needed to find a modern communications alternative. The solution? Mobile computers featuring full-time wireless data access via modems.

Each system runs on cellular digital packet data (CDPD) networks, which relay packet-based data via circuit-switched cellular systems. Both Bell Atlantic Mobile and AT&T Wireless Services offer all-you-can-eat services in major metropolitan areas throughout the United States. Other carriers include GTE, Bell Mobility, MT&T, Comcast, Vanguard, SNET and SBC. Individuals, corporations and government agencies can subscribe to CDPD service, gaining a full-time connection to the Internet or to private networks with the same security protocols available for landline-based Internet services.

Each packet is transmitted independently and carries its own destination and error-correction information. Thus, packet networks perform well in systems with variable traffic and channel quality-common conditions in the wireless environment. Furthermore, service is available when the user is moving or in a fixed location.

Both the Philadelphia and Utah Police Departments adopted systems using Sierra Wireless’ MP200 ruggedized, trunk-mounted modems. The MP200 is designed for high-power performance and is engineered to withstand vibration, extreme temperatures, ignition noise, humidity and physical shock.

Finding felons in Philly The Philadelphia Police Department introduced the MP200 slowly, beginning with a pilot program that included 50 mobile data computers (MDCs) connected directly to the department’s central data system via Bell Atlantic’s CDPD network.Less than 12 hours after the first MDC had been instal led, the system began paying off. Two officers had observed a motorist behaving suspiciously, and one of them ran the license plate using the department’s newest tool. Within seconds, the officers knew the car had been stolen.

“They were very excited and informed dispatch that they had a ‘hit’ on their MDC,” Brennan said. “They pulled the car over. The driver tried to run, but the officers were able to chase him down.”

The new MDCs allowed officers to access criminal and vehicle records through local databases as well as through the National Crime Information Center, freeing up the once-overburdened airwaves. The pilot program was such a success that the department soon expanded it and ordered 650 additional MP200s.

“A big plus with the MDCs is that the car-to-car messaging is secure,” Brennan said.

“Many officers don’t want to go on the street without wireless data communication anymore. To them, it’s almost as important as their guns.”

Up-to-date in Utah West Jordan also saw the benefits of transmitting information securely, when the department chose CDPD services through AT&T. Another plus for the department was that transmissions are RSA-encrypted and Internet protocol-based, offering simple, secure access to local area networks (LANS) and Internet-based law enforcement databases.

West Jordan installed Toshiba laptop PCs, the MP200s and a Premier Mobile Data Terminal Talk-Thru RF server from Software Corporation of America. This newly installed system allowed officers to communicate information in real-time without going through the Valley Emergency Communications Center (VECC) or a headquarters server. Now, VECC dispatchers function as a backup information source instead of the constant liaison between officers. The dispatchers are free to focus their energies on the incoming 9-1-1 calls.

Following West Jordan’s lead, other Utah police departments began installing wireless data systems. Currently, more than 300 vehicles from the South Jordan, Midvale, West Valley, Murray and Sandy Police Departments-along with the Salt Lake City Fire Department, Highway Patrol, DEA and Sheriff’s Office-are using CDPD-based wireless data access. West Jordan maintains the email server for CDPD service.

“This system has created communications between departments that wasn’t there before,” Bates said. “We pass along 20,000 to 25,000 messages between that switch daily. Now, if we have a stolen car here, we can replicate the message to everyone.”

The Utah Highway Patrol’s tasks range from traffic enforcement to providing security for the governor’s office. The department uses Sierra Wireless AirCard 210s, which offer multimode communicatios via a pair of PCMCIA cards that fit into adjacent Type II slots on laptop PCs. Troopers can submit time sheets and reports, as well as make on-the-spot background checks on suspects while they are on the road.

Speeding response at the Springs Altamonte Springs also opted for the AirCard 210, which allows officers to read relevant data about each 9-1-1 call to assign themselves to the case in real time. Now, little time is wasted by having to repeat and confirm basic information.

With wireless data access, officers can expeditiously run checks from their vehicles. Officers can complete checks on stolen cars within three seconds, blistering speed compared to the two-minute wait for voice queries.

Altamonte Springs officers also enjoy the improved public and officer safety that the PCMCIA cards bring. Quick access to federal criminal databases allows officers to check plate information before approaching the vehicle, thereby increasing officer safety.

“The biggest benefit of this is that we are giving our officers the proper tools to do their jobs,” said Lt. William Telkamp, watch commander, Community-oriented Police Services. “In return, we are achieving a higher standard for public safety and ensuring the safety of our officers is maximized.”

It is this concern that persuaded Altamonte Springs to convert its system to MP200s with a global positioning system (GPS) option.

“We feel the MP200s with GPS will increase officer safety,” said Telkamp. “If something happens that wasn’t radioed in, we’ll at least have a starting point of where to search.” Telkamp also feels that response time to citizens’ calls for help will be minimized.

“If a robbery happens at a certain place, the dispatcher can determine what officer is closer to the scene and assign it to that officer,” Telkamp said. “We can also set up a perimeter easier to catch a suspect more efficiently.”

Altamonte Springs plans to install the MP200s in 30 patrol vehicles and 10 motorcycles. The trunk-mounted devices will be placed in the motorcycles’ saddlebags or in their equipment boxes, which already house the sirens.

Efficiency and safety In all three police departments, mobile data solutions have alleviated existing problems with voice communications. The systems arm officers with quick access to information, giving them a heads-up on the particulars of the person or vehicle sitting before them, while keeping voice communications free-and-clear.

“Our wireless communication solution has allowed us to become more resourceful, while increasing officer and public safety,” Telkamp said. “We want to do more, do it faster and more efficiently.”

Brennan is satisfied as well. “Our MP200s have proven to be almost flawless, and we are extremely happy with the product,” Brennan said. “The system has been a home run for us.”

Police departments will have expanding requirements for flexibility of a self-contained Internet access device and the high-power and GPS options of PC cards. To meet these needs, Sierra Wireless has designed the AirCombo 350, which merges a Type II network interface card supporting Windows 95, 98 or NT with a vehicle-mounted power amplifier that increases the interface card’s output power from 600mW to a full 3W. This system allows officers to access information from their laptop while inside or outside their vehicles.