Ericsson MINI-LINK BAS, Техническое описание, Страница: 155 / 174

9-9 MINI-LINK BAS
EN/LZB 111 0542 P2B Technical Description
9.3 Test Loops
A set of physical loops is managed within the MINI-LINK BAS,
focusing the segment between the RN and the AT. These loops are
used with the system in off-line condition, because their use means
traffic loss.
They are local loops only, RN side, they are defined by EM operator;
AT side, from the operator during the installation phase, to verify the
AT functionality using the ACT.
Generally the loop facilities are used to check the system after
installation, or an RN and AT replacement following a failure. Both in
case of traffic absence condition, for the entire RN or for the single
AT.
CE
Modem + MAC
ATM
HW Loop
I/F Loop
Radio
R/F Loop
FlexNU
AT
RN
Radio
R/F Loop
Modem + MAC
I/F Loop
ET
NCU
R-AAS
Figure 9-2 RN Near-End Loops and AT Near-End Loops
9.3.1 RN Near-End Loops
The RN near-end loops are used to find out if indoor or ODU, RN
side, are faulty. The following near-end loop tests are available:
•
I/F test loop
•
R/F test loop
The I/F loop is used to verify if, at intermediate frequency level,
indoor part, NCU, the RN is working correctly. The R/F loop is used
to check if, at radio frequency level, outdoor part, RAU, the RN is
working properly.
9.3.2 AT Near-End Loops
The Access Termination (AT) near-end loops are used to find out if
IDU or ODU, AT side, are faulty. The following near-end loop tests
are available:
•
I/F test loop
•
R/F test loop