Man-to-man detection with wireless sensors

I need to contact a company which manufactures a stand-alone wireless device (RFID, Bluetooth, Zigbee or any other wireless technology) which detects the presence of a similar device in a configurable detection range from 1 meter to 20 meters. Each device should have a relay output, which will be activated when another device is detected. The device must be able to detect one or more other devices at the same time, without any limit. The application is about tagging people with these devices and activate the relay when a person is close to any other, in order to activate a third-party device. The company should not have any sales representative in Spain and the product must have been developed more than one year ago.