This document describes methods, apparatus, and systems that relate to enable Authentication and Key Management for Application service for roaming users. In one example aspect, a method for wireless communication includes receiving, by a network device in a first network from a network device in a second network, a signal indicative of an authentication result related to a wireless device, wherein the signal includes a first key and an indication in case that the first network is different from the second network; and generating, by the network device, a key related information based on the signal.