User's Manual

2. System Description 2-11
© 2012 Moseley, Inc. All Rights Reserved. 602-16620-01, Rev. A
converts the received signal, provides additional filtering, and outputs an IF of 140 MHz
to the IF Processor.
The EVENT 5800 digital radio modem performs QPSK, 16-QAM, 32-QAM, 64-QAM, 128-
QAM and 256-QAM modulation and demodulation of the payload and forward error
correction using advanced modulation and coding techniques. Using all-digital processing,
the IF Modem uses robust modulation and forward error correction coding to minimize
the number of bit errors and optimize the radio and network performance. The IF Modem
also scrambles, descrambles and interleaves/deinterleaves the data stream in accordance
with Intelsat standards to ensure modulation efficiency and resilience to sustained burst
errors. The modulation will vary by application, data rate, and frequency spectrum. The
highest order modulation mode supported is 256 Quadrature Amplitude Modulation
(QAM). Table 2-5 summarizes the TCM/convolutional code rates for each modulation type
supported by EVENT 5800.
Table 2-8. TCM/Convolutional Code Rates
Modulation Type
Available Code Rates
QPSK 1/2, 3/4, 7/8
16-QAM 3/4, 7/8
32-QAM 4/5, 9/10
64-QAM 5/6, 11/12
128-QAM 6/7, 13/14
256-QAM 7/8, 15/16
The major functions of the EVENT 5800 include:
 I/O Processing – EVENT 5800 comes with a standard I/O capability that includes
support for up to 16xT1/E1 and 2x100Base-TX user payloads, 2x100Base-TX for
SNMP. In addition, option cards for DVB-ASI, DS-3/E3/STS-1, 1-2 x STM-1/OC-3, and
4xDS-3/E3/STS-1 may be added. The EVENT 5800 architecture is flexible and allows
for the addition of other I/O types in the future.
 Switch/Framing – EVENT 5800 includes an Ethernet Switch and a proprietary
Framer that are designed to support 1+1 protection switching, ring architecture
routing, and overall network control functions.
 Network Processor – EVENT 5800 includes a Network Processor which performs
SNMP and Network Management functions.
 Modem/IF – The EVENT 5800 modem performs forward-error-correction (FEC)
encoding, PSK/QAM modulation and demodulation, equalization, and FEC decoding
functions. The IF chain provides a 350 MHz carrier and receives a 140 MHz carrier.
Two modems can be used for 1+1 protection or ring architectures.
 Power Supply – The EVENT 5800 power supply accepts 48V DC and supplies the
EVENT 5800 and radio transceiver with power. A second redundant power supply may
be added as an optional module.
For the OC-3 configuration, a user rate clock is recovered from clock recovery NCO and
provided to the OC-3/STM-1 I/O card. The Modem Processor and its associated RAM,
ROM, and peripherals control Modem/IF operation. It also provides configuration and
control for both the IF and I/O cards. EVENT 5800 interfaces with the internal Radio
Transceiver to receive and provide modulated transmit and receive waveforms.
The 256-QAM Modem performs the modulation and demodulation of the
payload/wayside/SNMP data and forward error correction using advanced modulation and