FIELD: radio engineering, communication.
SUBSTANCE: request for opportunities services is presented. It includes a request for service opportunities exchange, where the services are associated with two users via the first signalling protocol; a response to the request for service possibilities, adopted by the first user device as a rejection of opportunity services request; provision of the second user device with an invitation to the service possibilities exchange with a request for service possibilities exchange, where the services are associated with two users through the second signalling protocol; the second user is identified as one, that the first user cannot communicate with if an invitation to service opportunities exchange does not lead to the requested exchange, or identified as one, that the first user can communicate with, if an invitation to service possibilities exchange leads to the requested exchange.
EFFECT: detection by the first user of the second user with RCS, even if the address directory represents it, as without RCS possibilities.
27 cl, 10 dwg
