Authentication of devices in a wireless network

A method for authentication of devices (D, D, D) in a wireless network, wherein-a device (D, D, D) periodically switches its mode from a read mode, in which it is able to receive authentication data from one or more other devices (D, D, D), to a write mode, in which it sends out authentication data to the one or more other devices (D, D, D), according to a random time slot scheme, -the device (D, D, D) authenticates itself after having received authentication data from another device (D, D, D) during the read mode, and-the device (D, D, D) switches permanently its mode to the write mode after being authenticated.