Routing in a radio access network connected to a plurality of core networks

The invention claims a method for in a wireless access network and executing mechanism of which with a wireless access network with multiple core networks' communication system for. In turn to realize capable of providing a service and login request in the middle of operating from the core network device, and rejection of login request, a first login request selecting core network of receiving. A login request to retransmit to the second core network, and responds at least one predetermined standard to obtain to, informs to the core network login request to providing service of the core network, wherein it is the login request and routing to the core network.