User Manual

AS4000 Operations and Maintenance
Section
605-0000-431
3
. Issue 1.6. Date3/2/99
Page 15 of 22 © Copyright Airspan Communications Corporation 1999
2.1.11. Loss of communications with ST
Message: ‘Modem Card:Lost Comms With ST’
Source: CT modem, slots 3 - 10 in the CT modem shelf.
Fault Condition: A ‘loss comms with ST’ message is forwarded to the EM if the CT
modem fails to establish a radio link with the ST.
This message is forwarded after a power-on reset of the CT rack/modem shelf.
Likely Cause: a. Loss of communications with any dependent ST, i.e. loss of frame
synchronisation and/or CMDA code synchronisation, detected by
the CT modem, or by the ST and sent to the CT modem on the
management channel when possible.
b. Radio path is blocked or the ST is faulty.
Consequential Effect: (a). If the message is generated due to the power on reset, an
‘Alarm clear’ message is sent to the Sitespan when the radio link is
established with the ST.
(b). If the problem is due to a temporary radio blockage, an ‘event
clear’ message is sent to the Sitespan when the radio path is cleared
and the ST can re-establish the link.
Repair Actions: Use the flowchart on the next page to decide the probable cause and
location of the failure.
• Establish whether one or many ST’s are affected.
• If a number of STs are affected it is probable that the fault is at the CT.
• If STs are affected on more than one shelf it is probable that CT common
components (Combining Shelf, Antenna, Feeder etc.) are the cause of the fault.