Level-1 NEC Microwave Link Troubleshooting Guide
NEC Microwave Link Troubleshooting You need to carry out following steps during troubleshooting of a NEC PASOLINK V4 Link.
i.
Power Physical Check of IDU & ODU Alarm Indoor Installation Outdoor Installation Media Route
Power Check Table 1-1 Equipment Power Check
Item
ii.
Maintenance guide
Toggle Power Switch
Observe the toggle power switch is ON or OFF,
IDU Fuses Check
If Toggle switch is OFF, first check IDU fuses & replace them if found expired. Now ON toggle Switch
Power Indicator (LED)
Observe the green power indicator on the front panel of IDU, ON or OFF,
Specifications
In normal condition, it is ON
In normal condition, Fuses are ok (Two extra Fuses are available with IDU) Normally, Green LED glows if there is no power issue and IDU’s fuses are in working condition.
Physical Check of IDU & ODU Alarm There are some steps to check IDU & ODU alarms physically & necessary troubleshooting steps as per alarm indications as mentioned below.
Table 1-2 Physical IDU & ODU alarm check with initial troubleshooting steps
Item
Maintenance guide
Specifications
IDU Indicator (LED)
Observe the red IDU LED indicator on the front panel of IDU
ODU Indicator (LED)
Observe the red ODU LED indicator on the front panel of ODU
Under normal conditions, this Red IDU indicator is off. (If all configured E-1 are used for traffic or hard loop otherwise it will glow) If this Red IDU indicator is ON, then note either it is just glowing or blinking. (If all configured E-1 are used for traffic or hard loop otherwise it will also glow) If it is only glowing, then check via software either traffic is affected or not. In case of IDU LED blinking (ODU LED will also blink with blinking of IDU LED), first check the connectivity of IF Cable. If IF Cable connectivity is not OK then refresh the IF Cable connector on respective site. Under normal conditions, this Red ODU indicator is off. If this Red ODU indicator is ON then observe either it is just glowing or blinking. If it is only glowing, then check via software either RSL value is affected or far end is turned OFF. In case of ODU LED blinking (IDU LED will also blink with blinking of ODU LED), first check the connectivity of IF Cable. If IF Cable connectivity is not OK then first refresh outdoor IF Cable connectors on respective site, again check IF Cable connectivity, if still not ok, also refresh Indoor IF Cable connector. If RSL is out of designed RSL value then realign this link from affected site which RSL value is down, after achieving designed value, lock the Antennas properly. If far end is powered OFF then first check its far end with same steps.
iii.
Indoor Installation Check Table 1-3 Check Indoor Installation Item
Maintenance guide
Specifications
Check the Indoor Installation including Indoor Installati on
•
Routing of power cable,
Tributary cable,
•
•
•
Indoor IF Cable routing Tightness of Indoor IF Cable connector and groundings
All indoor installation & equipment grounding should be properly routed & terminated at specific locations
iv.
Outdoor Installation Table 1-4 Check Outdoor Installation. Item
Maintenance guide
Specifications
Check the outdoor installation including •
•
Outdoor Installation
IF Cable routing, IF Cable groundings & their weather proofing
•
Antenna Tightness
•
ODU grounding
•
Outdoor connector tightness and its weather proofing
Antenna & outdoor connector should be properly tight, ODU and IF cable should be properly grounded.
If RSL value is not as per designed value due to looseness in Antenna, realign specific Antenna & tight it properly after realignment.
v.
Media Route Check Table 1-5 Media Route Check
Item
Maintenance guide
Specifications
If there is no issue in MW Link but media is not ok •
•
Media Check (Local MW Link and media route from site to BSC)
•
•
•
•
First loop faulty E-1 towards BTS If BTS E-1 Cable is ok, Hard loop faulty E-1 of this local link to check this link media is OK or Not If local link media is ok then give loop towards BSC from that site & note your observation, it is ok or not If this loop is not ok then move towards BSC site by site & check media by giving hard loop towards BSC & trace media fault where it exists. If there is any other media used to route this site traffic after local MW Link , first verify this media i.e. MW / Leased Line / ADM / VSAT If still media is found OK but site E-1 is not working properly, perform BER test for this specific E-1 & check the results.
First verify it that there is no media issue through which this site traffic is routed i.e. MW / Leased Line / ADM / VSAT
