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CFIP PhoeniX C Series TDM/IP Split Mount System Technical Description and Configuration Guide
•
Rev. 1.0
•
© SAF Tehnika JSC 2013
NOTE:
The ATPC function should be always OFF during the installation!
–
ATPC RX Level
– Required level for Automatic Transmit Power Control. Field specifies the optimal
receive level used for ATPC function.
–
ATPC
Status
– Status of ATPC loop.
-
off –
It indicates that ATPC function is disabled.
-
ok –
It indicates that ATPC loop has regulated required level.
-
out of range –
It indicates that ATPC loop cannot reach the required level.
–
TXIF Level
– Transmit IF level at ODU input (350 MHz) indicates the signal strength of IF input into
ODU. This level should be in the range of 0 dBm up to -30 dBm (low signal). By standard the
output TXIF level from IDU is 0 dBm. It is useful to check this value if that corresponds to
supposed cable attenuation.
–
Modem Sync
– Demodulator synchronization status is the basic indicator of proper function of
IDU receiver.
-
ok –
It indicates that demodulator is synchronised with received air-frame.
-
loss –
It indicates that demodulator is not synchronised with received air-frame.
–
MSE
– Mean Square Error is a basic quality of signal indicator. Used MSE value is normalized
presentation of MSE value. In absolute value it can be presented also as signal to noise ratio
when demodulated signal is close to sensitivity level. The lower the value is the better the signal
is. The parameter is usually in the range of -10 dB to -40 dB. If Modem sync is not in ok status,
MSE parameter might display the unpredictable values.
–
Modulation Limit
– Optimal modulation scheme selects either fixed modulation scheme for no-
ACM mode or defines the highest modulation scheme which can be used in ACM mode.
–
ACM
– Automatic change of modulation. When this mode is selected then hitless switch-over
among several modulation schemes is permitted in dependence on actual MSE level. IDU can
automatically work in all modulation schemes lower than or equal to modulation scheme
defined in Modulation Limit parameter.
–
RXIF Level
– Receive IF level at IDU input (150 MHz) indicates the signal strength of IF input into
IDU. This level should be in the range of -10 dBm up to -35 dBm (low signal). By standard the
output RXIF level from ODU is -10 dBm. It is useful to check this value if that corresponds to
supposed cable attenuation.
Especially the modulation scheme settings and the channel bandwidth affect the final data rate (data
throughput) and sensitivity (link distance) of microwave link. Generally speaking, the narrower
bandwidth and lower modulation then lower the data rate but greater the sensitivity are (see
Technical Specification document).
In dependence on the type of supplied license (limit for maximum data rate) the modulation type can
be changed (type of modulation can be set / changed up to a maximum transmission capacity).
Microwave link can be ordered with the different licenses in accordance with actual price list and
business policy. Then the transmission capacity can be changed in the range of 10 Mbps up to a
maximum data rate of supplied license, max. 365 Mbps for 1+0 mode.
Time-restricted license. For a limited period of time the microwave link can be supplied with a higher
type of modulation (with higher data rate), e.g. for temporary testing. After the expiration of this
period the maximum type of modulation is automatically downgraded to the default modulation from
license and the user data transmission capacity is disabled at all (0 Mbps). It does not affect the out-
of-band management channel.
The modulations are named according to the combination of the following parameters. Behind the
modulation code, there is written the overall Capacity – real data throughput. Modulation name
coding is described in the next example.
