In a conventional direct-mode communication system, apparatuses can communicate with each other directly, so messages can be exchanged more simply and rapidly. However, usually no complete security protocol is available for such direct-mode communications, so the direct-mode communications are liable to unauthorized use by malicious persons to forge identifications and to steal information. Accordingly, when the discovery interactive technology is used for the conventional direct-mode communication apparatuses, the security and the stability of these apparatuses will become a significant potential trouble.
Additionally, if it is desired to transmit interactive information to a user apparatus when the discovery interactive technology is used in the conventional direct-mode communication system, usually an interactive information request is firstly transmitted by the user apparatus to a nearby serving apparatus. Then, the serving apparatus transmits the interactive information request to a back-end core network so that the back-end core network broadcasts interactive information to the user apparatus. However, information transmission in this manner is not only relatively complicated, but is also likely to cause a burden on network resources due to redundant information transmission.
Accordingly, an urgent need exists in the art to enhance the security of the direct-mode communication system and increase the convenience of message propagation.