New NTP Audio Synchronization Feature for Digigram’s IQOYA IP Audio Codecs Improves Continuity of Radio Broadcasts

Available as an Option With the Latest Firmware Update, New Capability Enables Radio Broadcasters to Manage Delay Across Transmitter Sites for Seamless Listening Experience

GRENOBLE(20 Mar 2014)

Digigram today announced the release of a new Network Time Protocol (NTP) feature for the company’s IQOYA *LINK, IQOYA *LINK/LE, and IQOYA *SERV/LINK IP audio codecs. Facilitating audio synchronization via an NTP server, this feature allows radio broadcasters to assure a seamless audio experience for on-the-go listeners receiving signals from a series of different transmitters in a multiple-frequency FM network and to resolve the audio delay caused when adjacent transmitters receive signals from different sources, such as satellite and terrestrial IP links.

“Enhanced with the ability to synchronize audio based on NTP servers, the IQOYA line offers an elegant solution for a critical issue that can adversely affect the listening experience,” said Stéphane Bert, IP audio distribution product manager at Digigram. “Without relying on additional hardware, these IP audio codecs reduce the audio delay between two contiguous transmitters to as little as 20 milliseconds on a WAN and fewer than five milliseconds on a LAN. Guaranteeing constant delay, the systems allow broadcasters to compensate for delay and eliminate awkward gaps in audio.”

Installed across transmitter sites, Digigram IQOYA IP audio codecs ensure that when a radio program is transmitted using several FM transmitters in a multiple-frequency network (MFN), in which all transmitters use different frequencies, the audio delay between two contiguous transmitters remains small and constant. This prevents undesired audio effects for a person in a car listening to an FM receiver that switches from one transmitter to another.

When a transmitter site receives an audio program through a terrestrial IP network and a contiguous transmitter site receives the same audio program through satellite, the IQOYA products can significantly reduce the audio delay — sometimes as long as one second — between these two transmitters.

Each IQOYA unit can be upgraded via a simple firmware update to activate the optional NTP feature, which slaves the codec’s sample frequency to the clock reference given by the NTP server. The Digigram encoder can then make the associated decoder play out the audio at the same presentation time. Playback on the decoder can be delayed up to two seconds for unframed audio formats (PCM, Eapt-X) and six seconds for framed audio formats (MPEG layer 2 and 3, AAC). The smart synchronization on the incoming IP audio stream ensures a constant delay between the decoder and the encoder.

More information about Digigram and the company’s products is available at www.digigram.com or by phone at +33 (0)4 76 52 47 47.