Patent ID: 8239547
Filing Date: 2012-08-07
Classification: H04L

Abstract:
1. A method in an application server for providing different services and performing service changes in a multimedia communication system that includes the application server and a plurality of multimedia clients, the method comprising the steps of: receiving, by the application server on a session signaling channel, a request from a first multimedia client inviting at least a second multimedia client to be part of a multimedia session; receiving by the application server on the session signaling channel, a first set of supported media types from the first multimedia client, the first set of supported media types indicating a set of media types supported by said first multimedia client; sending on the session signaling channel from the application server to the second multimedia client, a request inviting said second multimedia client to be part of the multimedia session; receiving by the application server on the session signaling channel, a second set of supported media types from the second multimedia client, the second set of supported media types indicating a set of media types supported by said second multimedia client; storing by the application server, the sets of media types supported by the first and the second multimedia clients; receiving by the application server on a media control channel that is distinct from the session signaling channel, a transmission request from a transmitting multimedia client in the multimedia session requesting to transmit a first media stream towards a receiving multimedia client in the multimedia session, the transmission request comprising a first set of requested media types, wherein the transmitting multimedia client is one of the first or the second multimedia clients and the receiving multimedia client is another one of the first or the second multimedia clients; comparing by the application server, the first set of requested media types with the stored supported media types for the receiving multimedia client to verify that the first set of requested media types is supported by the receiving multimedia client; sending on the media control channel from the application server to the transmitting multimedia client, a first grant allowing one or more of the first set of requested media types, indicated as a first set of allowed media types; receiving by the application server, the first media stream from the transmitting multimedia client, the first media stream including one or more media types of the first set of allowed media types; re-transmitting by the application server, the first media stream to the receiving multimedia client; during the multimedia session, receiving by the application server on the media control channel, a service change request from the transmitting multimedia client requesting to transmit a second media stream to the receiving multimedia client without re-establishing the multimedia session, the service change request comprising a second set of requested media types; comparing by the application server, the second set of requested media types with the stored supported media types for the receiving multimedia client to verify that the second set of requested media types is supported by the receiving multimedia client; sending on the media control channel from the application server to the transmitting multimedia client, a second grant allowing one or more of the second set of requested media types, indicated as a second set of allowed media types; receiving by the application server from the transmitting media client, the second media stream in addition to the first media stream, the second media stream including one or more media types of the second set of allowed media types; and re-transmitting the second media stream from the application server to the receiving multimedia client in addition to the first media stream.