User's Manual

Technical Description & Configuration Guide Detailed Configuration in Web
LigoWave Page 40
In comparison similar system using 32QAM and providing similar capacity would provide only 99,981%
of availability. Besides, lack of ACM would not provide higher availability. You would have to decrease
the distance, decrease modulation or increase antenna sizes to achieve 99,995% availability for the
given link.
This example demonstrates how the new technology, based on an ACM mechanism, can play a key
role in the development of cost-effective next-generation wireless access networks, by taking
advantage of traffic evolution from synchronous TDM traffic to packet IP-based traffic.
The wide option allows increasing overall capacity of the link in terms of deteriorating RSL sensitivity
threshold. Note, that using 32APSK with total capacity of 100Mbps, LigoPTP 24 automatically uses
"better sensitivity" mode, but incrementally enabling E1 channels, LigoPTP 24 adapts it's forward error
correction, till the maximum 108Mbps capacity (100Mbps Ethernet + 4E1) is enabled and LigoPTP 24
operates in "wide" mode. For more details refer to table in chapter Cable Requirements.
Loopback Configuration
Loopback tests are accessible using local or remote management methods.
For safety purposes all loopbacks (local and remote) can be set on a fixed time interval only. If no time
interval is specified, the default value is 60 seconds (1 minute).
Figure 28 – Loopback Modes
 E1 loopback mode loops signal back to local end in bounds of E1 interface. E1 loopback mode
must be set on the particular channel you are wishing to test. If no E1 channels are selected, E1
loopback mode is not available;
 NEAR loopback mode loops signal back to local end after the modem;
 IF loopback mode loops signal back to local end by linking intermediate frequencies.
Loopback  allows choosing loopback mode and its activity time in seconds (command line 
loopback) {status | none | if | modem | e1{1|2|3|4}} [<time>]);
Pressing Execute configuration applies changes made to the corresponding section only for the local
side LigoPTP 24 FODU. If Rollback on is selected, configuration will be reverted in case of erroneous
configuration changes applied.
Write to config file  writes to configuration file all the changes made on the whole page (command
line  cfg write);
FODU returned - in case of error or incorrectly entered parameter value, or other problems on the
whole page  
Additional radio and modem configuration commands in Telnet/serial interface is provided in the table
below: