1. A semantic negotiation module of a terminal that is designed by a first service provider, the semantic negotiation module comprising: a processor; a communication manager configured to transmit, to a service server designed by a second service provider, a service request message requesting an optimized service, and configured to receive, from the service server, a constraint query message with respect to a constraint for performing the optimized service; and a semantic negotiator configured to extract a value of the constraint, based on at least one of user ontology and terminal ontology, wherein the communication manager transmits, to the service server, the value of the extracted constraint, and receives, from the service server, information about the optimized service, and the at least one of the user ontology and the terminal ontology enables the terminal and the service server to interact even when the first service provider is different from the second service provider.