SAF CFM-LM Series, Technical Description

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I N D O O R U N I T
38
Cable Interface
The cable interface provides the power supply voltages for all blocks and the ODU. Since the DC-
DC of the power supply is isolated, the supply voltages of the device may be positive or negative in
respect to the ground.
Like the ODU, the extra telemetry data flow is transmitted using the method of the pulse-
amplitude modulation.
The received 140 MHz signal (from ODU) is demodulated in the frequency demodulator, from
which the signal is fed to the MUX module.
From the MUX module the four level data signal is passed to the 350 MHz voltage controlled
generator. The carrier-modified signal is passed through the buffer amplifier and the band pass
filter to the cable, which is connected to the ODU.
Base-band Modem
Base-band modem performs coding, decoding and scrambling of the four level data signal.
Management Controller
The management controller provides the control of and checking of the IDU and ODU, as well as
the management and monitoring functionality. Management controller contains TCP/IP stack and
acts as an IP packet router for management traffic. There is Web page, SNMP agent and Telnet
client/servers implemented providing comprehensive management functionality and allows to
integrate the CFM equipment in any telecommunications network easily.
Multiplexer (MUX)
The multiplexer module performs multiplexing and demultiplexing of the WAN data channel into
interface traffic channels and 16 kbps telemetry channel.
Traffic Interfaces
The traffic interface provide physical interface between user equipment and the multiplexer.
For modular IDUs (MUX and REBM type IDUs) special traffic interface modules are available:
−
the E1 interface module : single E1 port module which terminates G.703 2 Mbps channel;
the E1 interface module provides two types of traffic port connectors: 120
Ω
balanced
interface on RJ-45 type connector and 75
Ω
unbalanced interface on BNC type connectors (a
pair of coaxial cables with the BNC type connectors are required);
− the V.35 interface module is provided with M.34 standard connector. The V.35 module
terminates 2, 4, 6 or 8 Mbps from multiplexer and provides user configurable data rates of 64
kbps, 128 kbps, 256 kbps, 512 kbps, 1024 kbps, 2048 kbps, 4 Mbps, 6 Mbps or 8 Mbps to
single V.35 interface;
−
the Remote Ethernet Bridge module (REB module). The REB module terminates 2 Mbps,
4 Mbps, 6 Mbps or 8 Mbps from multiplexer and provides single 10 Mbps 10Base-T Ethernet
port on the LAN side. The REB interface module contains a complete filtering Ethernet
bridge.
Ethernet Interface Board
The Ethernet interface board has a built in two-port packet switching engine. One of the ports is
10 Mbps on 10BaseT Ethernet interface (implemented as RJ-45 type connector). The other port is
synchronous serial interface that is terminated in the baseband modem, hence the full capacity is
terminated in the Ethernet interface board from the Radio Unit.