For example: Agilent E4440A or Anritsu 68369
Spirent NetCom GPS
Spirent NetCom GSS4100
Spirent NetCom GSS4100 GPS/SBAS Signal Generator
Manufacturer: Spirent NetCom
Spirent NetCom GSS6100
Spirent NetCom GSS6100 GPS/SBAS Signal Generator
Manufacturer: Spirent NetCom