Monnit's Alta remote monitoring system uses an Ethernet or Cellular Gateway or Software as the conductor of the system. Then you can add Alta sensors as needed. The Alta Gateway receives the sensor wireless data, then sends it to the cloud service or software. Each location requires one or more gateways that act as receivers for the sensors. Available to purchase from Absolute Automation, a Monnit cellular SIM and service are necessary for cellular gateways. A cloud account and subscription are required for all gateways, as does local software that has a license.