ALM-26121:GPS Antenna Fault
This alarm is reported when the cable between a satellite card and an antenna system is open-circuited or short-circuited and this fault lasts for a period of time (40s by default). This connection involves the feeder, antenna, and surge protector. This alarm is cleared when the connection recovers and remains functional for a period of time (180s by default). The alarm filtering parameters can be set by running the SET ALMFILTER command. For RGPS, this alarm is reported when the system detects that the supply voltage for the RGPS is too high or too low. This alarm is cleared when the system detects that the supply voltage for the RGPS becomes normal.

For more handling procedure, please refers to below link:
http://support.huawei.com/hedex/hdx.do?docid=EDOC1100016116&id=aalm-26121&text=ALM-26121%2520GPS%2520Antenna%2520Fault&lang=en