Field tests of conditional access of an IBOC system began this week on WUSF(FM), Tampa, a longtime-Ibiquity test bed and the first public station to go HD Radio.
WUSF personnel involved include station manager Tom Dollenmayer, engineer Mike O’Shea and Dustin Hapli. Representatives from Harris, Ibiquity Digital, NDS and NPR Labs have been at the station since the weekend to work on the tests, which started Sunday night. Representing NDS are Tom Rucktenwald and Bob Hadden; Ibiquity’s Pat Malley and Girish Warrier are working on the project. Contract engineer Tim Anderson, President, TBA Communications, is helping Ibiquity on the project.
The IAAIS is involved too. WUSF is transmitting its radio reading service on both its analog SCA as well as its HD3 channel.
The process of “permissioning” a receiver to access the protected channel is being tested and there’s no detrimental effect on the audio quality by the encryption process, Hal Kneller of Harris told me. The station is running dual 48 kbps on its main HD channel and HD2 channel and operating on the extended hybrid carriers at 24 kbps on the HD3 channel, he said. They’re turning on and off the equipment that encrypts the signal to see how the digital sounds and if it affects the analog SCA at all; it doesn’t, Hal says.
I asked him how the audio quality was at 24 kbps.
“It sounds almost as good as analog FM. It’s in mono. There’s no static or hiss and all distortion is gone.”
By the time results of these tests are shared at the upcoming NAB show, proponents hope to refine the user interface — a Web browser — that stations would use to operate the conditional access technology.