4/18/11
888-2587-001
1-3
WARNING: Disconnect primary power prior to servicing.
Section 1 Introduction/Specifications
FM HD Radio System
1.3
Glossary
Below are some terms associated with the FlexStar™ HD Radio architecture.
Customer LAN/WAN vs. Dedicated Ethernet
- Subnetting and using a router can be
used to keep all non-HD Ethernet traffic away from the FlexStar equipment.
AAS
- Advanced Applications Service. Non-program related data services encoded into
the HD bitstream and include Supplemental Audio, traffic information, news, weather,
stock quotes, etc. The first AAS to be implemented in HD receivers will be
Supplemental Audio channels. The HDI-100 receives, manages and multiplexes all
AAS services for HD Radio.
AES3
- Abbreviation for Audio Engineering Society 3-1992 which is the established
standard for professional digital audio, conveying two channels of periodically sampled
and uniformly quantized digital audio on a single twisted pair wire with or without
transformer coupling. The recommended sample rate standard for HD Radio is 44.1
kHz. The abreviation AES/EBU refers to a compatible source or reciever with
transformer coupling.
API
- Application Programmers Interface. A set of programming commands used to
manipulate an existing program.
Dual Input Antennas
- a low loss method of developing an FMHD hybrid signal. Dual
input antennas utilize two RF inputs, one for FM and a second for the HD transmitter.
They combine the HD and FM signals and each element radiates a hybrid FMHD
signal.
CAT 5/CAT 6
- Unshielded twisted pair (UTP) wire that can operate at speeds up to 100
megabits per second/1000 megabits per second. Typically used to make an Ethernet
connection to a device, it is now also being used to transport AES3 audio.
Combiner Port Injector
- a low loss method that utilizes the broadband input port of a
constant impedance combiner system to inject the digital signal. Hybrids are then
utilized to combine the FM and HD signals and the resulting hybrid signal is then fed to
the antenna elements.
Common Amplification
- Also referred to as Low Level Combining. Common
amplification utilizes a single transmitter and it’s associated IPA and PA stages to
amplify a hybrid HD+FM signal that has already been combined with the proper power
ratios at the exciter stage.
EOC
- Ensemble Operations Center. The functional capabilities to manage the
transmission, configuration and status of all AAS inputs. See "1.3.1 Ensemble
Operations Center Description" on page 1-5 for further information.
