HOT SPRINGS -- The Hot Springs Police Department moved its radio traffic from the analog trunked system that had supported its communications for more than a quarter-century to a digital platform earlier this spring, completing the city's migration to the Arkansas Wireless Information Network.
But the city said the move to the state-run, 700-800 MHz frequency digital microwave-based interoperable communications system used by more than 900 federal, state and local agencies hasn't closed stubborn coverage gaps downtown and elsewhere.
The microwave dish Motorola was installing in the tower of the Army and Navy General Hospital three years ago promised to close the downtown gap, affording a strategic perch to propagate radio signals into and out of the hard-to-reach area of upper Central and lower Park avenues.
But the state abandoned the building, announcing in May 2019 the end of the residential vocational and job placement program for young adults with disabilities the building had housed since 1960.
The city planned to relocate the repeater to the city-county microwave relay site on West Mountain, asking the Hot Springs Board of Directors last spring to adopt a resolution in support of a $642,312 change order to the $5 million contract the city entered into with Motorola in November 2017.
But the item was pulled from the agenda after Motorola told the city the move to West Mountain would void coverage guarantees for the 100 to 700 block of Central Avenue, National Park College, the Hot Springs Convention Center, Bank OZK Arena, Arlington Resort Hotel & Spa and Lakeside and Langston elementary schools.
"We've done several studies trying to determine how we're going to get the dogleg on Central and how we're going to increase our coverage in the Lakeside area," City Manager Bill Burrough said Tuesday.
The consent agenda for the board's May 3 business meeting includes a ground lease agreement with the Lakeside School District for a microwave repeater site. The 150-foot monopole proposed for the north end of campus will be a key node in the city's AWIN infrastructure.
"This is the best as far as serving Lakeside and serving the surrounding areas," Fire Chief Ed Davis told the board Tuesday. "Lots of surveys have been conducted, from how well the microwave would work within the microwave ring we've established and how it will project signals to different radios that might be operating in the adjacent space."
The city expressed concern about AWIN's limited reach into downtown before the board awarding Motorola the contract for the communications upgrade. The Confederate monument rally held downtown in August 2017 showed AWIN's limitations, because Arkansas State Police personnel had difficulty communicating on their AWIN radios.
Putting a repeater in the hospital tower was seen as the solution, providing a primary communications point for downtown and Malvern Avenue and a key leg in the microwave chain linking the city to AWIN's communications core in Little Rock.
"AWIN communications are better than what they were prior to us putting our system in," Davis said. "There are still some areas we need to improve within the system. The loss of (the hospital tower) was a very critical loss to the system. It's nothing that cannot be remedied with good engineering, time and some money."
The city said about $1.6 million remains from the more than $6 million it set aside for the communications project. The 2.6-mill property tax the city levied during the 2016 and 2017 tax years provided $3.54 million for the project, with enterprise accounts such as the city's water, wastewater and solid waste funds paying the balance.
Police was the last city department to migrate fully to AWIN. Officers communicated on the analog and digital systems during the run-up to the migration. They toggled between the networks, as both were programmed into the dual and multiband P25-compliant APX radios the department received through the city's contract with Motorola.
Upgrades the city completed at its 911 call center allowed police to join other city departments as full-time AWIN users. The shift to digital gives users access to more channels and repeaters than the city's trunked legacy system provided.