Oklahoma City chooses EDACS for radio system upgrade
Oklahoma City has selected a new 800MHz M/A-Com enhanced digital access communications system to replace its replace 35 separate conventional radio channels. The new installation will support 4,500 radios on 32 trunked channels configured in two overlaid simulcast systems.
Kerry Wagnon, program director for the city’s Public Safety Capital Projects Office, administers $90 million worth of improvements approved by voters that include the purchase of vehicles and other apparatus, an upgrade to computer-aided dispatching and the $24.5 million EDACS radio system. A sales tax is funding most of the radio system, with the rest paid by the city’s airport, water and utility, and transportation and parking enterprises. They will share the system with other city departments and public safety agencies.
The 28-month deployment period began in January with acquisition and specification development for 11 new repeater sites that will work with a primary site on a 400-foot downtown building.
One system uses 18 trunked channels and a tower configuration that concentrates signal power overcome as much as 20dB of obstruction attenuation to penetrate buildings in densely populated areas. Wagnon said that the city preferred achieving in-building coverage with sites rather than bi-directional amplifiers in buildings.
A second, 14-channel trunked system covers the same area but emphasizes rural coverage in the 620-square-mile city. Users will roam from one system to another if coverage from their primary system otherwise would deliver an inadequate signal. Meanwhile, the dual-system configuration offers redundancy.
M/A-Com officials pointed out that together with EDACS systems operated in the state by Oklahoma Gas & Electric and American Electric Power, nearly 90% of Oklahoma would be covered by the city’s and the utilities’ 800MHz EDACS radio service. Extensive EDACS coverage didn’t figure into the city’s decision, though. Wagnon said M/A-Com won the contract because the system rated higher on the evaluation criteria with a lower cost.
Moreover, Wagnon said that the majority of the 50 agencies identified in the request for proposal for communications interoperability use VHF and UHF conventional systems. Oklahoma City’s neighbors to the north (Edmond) and to the south (Norman) use 800MHz Motorola systems. Placing everyone on a new EDACS system didn’t seem feasible.
“EDACS gives us an audio switch with their causeway and mobile radios and other switches that accomplishes interoperability with disparate equipment,” Wagnon said. “Plus the causeway will make it easier for us to migrate from the 35 separate conventional systems now in use. You don’t flip the switch one day, taking everyone off of the old systems and putting them onto the new one. The causeway switch will allow us to migrate without a lot of pain. Also, it will allow us to talk with other agencies on VHF and UHF better than we could before. That’s one reason we liked EDACS.”
Wagnon added that the city liked the M/A-Com system’s redundancy requirements and its ability to dynamically assign control channels.
Wagnon said that the projects office received input from all of the city’s departments and achieved a unanimous evaluation. The steering committee, including the city managers, public safety department chiefs and various assistants, voted unanimous acceptance, and so did the city council. “To date, there have been no protests,” he said.
When it is completed, the new system will serve as the backbone of the city’s radio communications network, uniting communications among all city-wide departments including police, fire, public works, water and wastewater, airports, transit, parks and recreation, and other municipal officials. It will provide mobile and portable communications for police officers, firefighters and workers who provide services to the public, such as animal control officers, code inspectors, street maintenance and utility services.
M/A-Com will provide, assemble and integrate all of the project’s hardware and software, as well as provide both user and administrator training. With headquarters in Lowell, MA, M/A-Com is a unit of Harrisburg, PA-based Tyco Electronics.
