Systems and methods for implementing call pickup in a SIP environment

A method, performed by a network server, for providing call pickup in a communications system, the method comprising:

• transmitting a first message from the network server to a called party device, the first message initiating a call establishment between a calling party device and the called party device;
• receiving a second message at the network server from a third party device during the call establishment, the second message including a call pickup indication;
• canceling, via the network server, the call establishment between the calling party device and the called party device in response to the second message;
• establishing a dummy session between the network server and the third party device, the establishing a dummy session including:
• establishing an early media dialog between the network server and the third party device, the establishing an early media dialog including:
• sending a session initiated protocol (SIP) provisional response message from the network server to the third party device;
• transmitting a third message from the network server to the third party device, the third message initiating a call establishment between the calling party device and the third party device;
• receiving, at the network server, a fourth message from the third party device, the fourth message causing the network server to cancel the dummy session;
• and
• establishing a call between the calling party device and the third party device in response to the fourth message.

A server comprising:

• means for transmitting a first message to a first device, the first message initiating a call establishment between a second device and the first device;
• means for receiving a second message from a third device during the call establishment, the second message including a call pickup indication;
• means for canceling the call establishment between the second device and the first device in response to the second message;
• means for establishing a dummy session with the third device, the means for establishing the dummy session including:
• means for establishing an early media dialog between the server and the third device, the means for establishing an early media dialog including:
• means for send mg a session initiated protocol (SIP) provisional response message to the third device;
• means for transmitting a third message to the third device, the third message initiating a call establishment between the second device and the third device;
• means for receiving a fourth message from the third device, the fourth message causing the server to cancel the dummy session;
• and
• means for establishing a call between the second device and the third device in response to the fourth message.

A method for providing call pickup, comprising:

• initiating a call from a first device to a second device, the call being initiated over one or more networks, at least one of the one or more networks being a data network;
• storing information relating to the call initiation between the first device and the second device;
• receiving a message from a third device during the call initiation, the message including a call pickup indication;
• retrieving the information relating to the call initiation between the first device and the second device;
• establishing an early media dialog between a network server and the third device, the establishing an early media dialog including:
• sending a session initiated protocol (SIP) provisional response message from the network server to the third device;
• and
• establishing, after establishing the early media dialog between the network server and the third device, a call between the first device and the third device based on the retrieved information.

A method for providing call pickup in a communications system, the method comprising:

• initiating a call from a first device to a second device, the call being initiated over one or more networks, at least one of the one or more networks being a data network;
• receiving a message from a third device during the call initiation, the message including a call pickup indication;
• canceling the call initiation between the first device and the second device;
• establishing an early media dialog between a network server and the third device, the establishing an early media dialog including:
• sending a session initiated protocol (SIP) provisional response message from the network server to the third device;
• and
• establishing, after establishing the early media dialog between the network server and the third device, a call between the first device and the third device, the first device being unable to initiate call pickup.