HD Link Installation & Operation Manual
2 – Functional Design
Version 2, April 2010
2-6
Harris Corporation
Intraplex Products
2.3 HD Link Features
2.3.1
Audio Transport
The HD Link audio transport includes
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Selectable sampling rate.
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Coding type.
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Number of channels.
Audio input can be either AES/EBU or analog. Outputs have simultaneous AES/EBU and analog. Two
additional channels offer ITU G.722 compatible audio and asynchronous auxiliary data for remote
control applications.
The HD Link STL uses these features to give top-notch, multi-channel audio performance:
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One or two stereo main program channels, each available with linear uncompressed or Enhanced
apt-X compressed audio
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32, 44.1, or 48 kHz sample rates (you select which) transporting 15, 20, or 22 kHz audio
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Two monaural, 7 kHz audio channels with G.722 coding available for AM, radio reading services,
SCA, Emergency Alert System (EAS), and other auxiliary audio applications
2.3.2
Data Transport
Designed for IP data transport, the HD Link STL manages all HD Radio transport scenarios, regardless
of where you place your importer and exporter. Its two prioritized Ethernet paths give preference to
HD Radio data over control and other LAN/WAN data. This system supports both UDP and TCP and
handles the switching of TCP return packets over asymmetric IP paths with plug-and-play simplicity.
The integral TCP support provides HD Radio transport under 30 times higher bit rate error (BER). TCP
return packets use IP tunneling to securely traverse third-party networks like ISPs without revealing
private addresses. Layer 3 switching supports an asymmetric TCP return path for integrated “plug and
play” support for TCP wherever a return path exists.
The HD Link system has an integrated IP gateway designed for transport of HD Radio compatible IP
streams. With IP prioritization, the system carries other IP data, such as control signals and LAN
traffic, separately from the high-priority HD Radio stream.
Dual domain access control provides tight security. One access list controls HD Link units and the
other access list manages the firewall to keep unwanted traffic off the transport link. An intuitive
graphical front panel interface and an embedded Web server for a remote user interface provide
multiple setup, control, and monitoring options.
This STL system transports data through
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Integrated IP channel for HD Radio (Importer-to-Exporter or Exporter-to-Exciter).
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At least three times the nominal IP data throughput of other digital STLs.
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Suitable for use of private and public networks without requiring an external adapter to work with
an external TCP return path.
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The capability to take advantage of available IP audio paths to provide integral backup in the
event of radio link failure.
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Two prioritized Ethernet ports: high priority for HD Radio traffic and low priority for control data
and LAN traffic.
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An RS-232 asynchronous data channel, up to 9600 bps, on each main program audio channel.
2.3.3
RF Performance
The HD Link system gives powerful, reliable RF performance with
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1, 2, or 5 Watts RF power.