An apparatus includes a network interface that receives a registration request and an event notification, the registration request indicating an identity of a sensor and a physical location of the sensor, the event notification identifying a location of an event. The apparatus also includes a processing unit that determines a first geofence, at least in part based on the location and a distance from the location. The processing unit determines that the sensor is within the first geofence, at least in part based on the physical location of the sensor. The network interface transmits a request indicating the sensor and receives a response including data associated with the sensor.