CLIAMS:1.A method for establishing a call between a caller and a receiver, the method comprising: generating, by a communication system (112), a call request for being sent to the receiver for joining the call as an audio participant, wherein the call request is generated when a video call request sent by the caller is rejected by the receiver;
performing, by the communication system (112), negotiations pertaining to media capabilities with the caller and the receiver upon receiving an acceptance of the call request; and
upon successful media negotiations, assigning, by the communication system (112), a call address for establishing the call between the caller and the receiver, wherein the caller joins the call as a video participant.
2.The method as claimed in claim 1 further comprising storing, by the communication system (112), the video call in a video server (118), wherein a video stream of the caller is mixed with an audio stream of the receiver before being stored in the video server (118)
3.The method as claimed in claim 2, wherein the storing comprises establishing, by the communication system (112), a session between the communication system (112) and the video server (118).

4.The method as claimed in claim 3, wherein the establishing comprises sharing, by the communication system (112), the assigned call address with the video server (118).

5.The method as claimed in claim 1, wherein the performing comprises playing an announcement, by the communication system (112), indicating participation of the caller and the receiver as the video participant and the audio participant respectively.

6.The method as claimed in claim 1, wherein the performing further comprises establishing, by the communication system (112), a session with the caller and the receiver for sharing at least one of an audio stream and a video stream.

7.A communication system (112) for establishing a call between a caller and a receiver, the communication system (112) comprising:a processor (202); a request processing module (212), coupled to the processor (202), to,
generate a call request for being sent to the receiver for joining the call as an audio participant, wherein the call request is generated when a video call request initiated by the caller is rejected by the receiver; and
receive a response to the call request from the receiver, wherein the response is one of an acceptance and rejection of the call request; a negotiation module (214), coupled to the processor (202), to perform negotiations pertaining to media capabilities with the caller and the receiver upon receiving the acceptance of the call request; and
an assignment module (216), coupled to the processor (202), to,
assign a call address to the call, based on successful media negotiations; and
share the call address with the caller and the receiver for establishing the call between the caller and the receiver.

8.The communication system (112) as claimed in claim 7 further comprising a mixing module (218), coupled to the processor (202), to,
establish a session with a video server (118);receive a video stream from the caller and an audio stream from the receiver; and
merge the video stream and the audio stream for being stored in the video server (118).

9.The communication system (112) as claimed in claim 7, wherein the negotiation module (214) establishes a session with the caller and the receiver for sharing of at least an audio stream and a video stream.

10.The communication system (112) as claimed in claim 7, wherein the negotiation module (214) performs negotiation with a video server (118) for joining the video call.

11.The communication system (112) as claimed in claim 7, wherein the caller utilizes a video supported device from a Global System for Mobile Communication (GSM) network, Universal Mobile Telecommunications System (UMTS) network, a Personal Communications Service (PCS) network, a Time Division Multiple Access (TDMA) network, a Code Division Multiple Access (CDMA) network, a Next Generation Network (NGN), an Internet Protocol (IP) Multimedia Subsystem (IMS) network (104), a Public Switched Telephone Network (PSTN), and Integrated Services Digital Network (ISDN).

12.The communication system (112) as claimed in claim 7, wherein the receiver utilizes a non-video supported device from a Global System for Mobile Communication (GSM) network, Universal Mobile Telecommunications System (UMTS) network, a Personal Communications Service (PCS) network, a Time Division Multiple Access (TDMA) network, a Code Division Multiple Access (CDMA) network, a Next Generation Network (NGN), an Internet Protocol (IP) Multimedia Subsystem (IMS) network (104), a Public Switched Telephone Network (PSTN), and Integrated Services Digital Network (ISDN).

13.A computer readable medium having embodied thereon a computer program for executing a method for establishing a call between a caller and a receiver, the method comprising: generating, by a communication system (112), an call request for sending the receiver for joining a video call as an audio participant, wherein the call request is generated when a video call request initiated by the caller is rejected by the receiver; performing, by the communication system (112), negotiations pertaining to media capabilities with the caller and the receiver upon receiving an acceptance of the call request; and
upon successful media negotiations, assigning, by the communication system (112), a call address for establishing the call between the caller and the receiver, wherein the caller joins the call as a video participant. ,TagSPECI:As Attached