METHOD AND APPARATUS FOR SERVER-SIDE ADAPTIVE STREAMING
A server-side adaptive streaming capability is provided. The server-side adaptive streaming capability supports adaptive streaming of a data object from a server toward a client via a Transmission Control Protocol (TCP) connection between the server and the client. The server has access to a plurality of versions of the data object having a respective plurality of encoding bit rates associated therewith. The server has a TCP congestion control mechanism running for the TCP connection. The TCP congestion control mechanism has information associated therewith. The server determines, using the information associated with the TCP congestion control mechanism running on the server for the TCP connection, a transmission bit rate expected to be supported by the client for the TCP connection. The server selects, based on the transmission bit rate expected to be supported by the client and the encoding bit rates associated with the versions of the data object accessible to the server, one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection. The server dynamically switches between the versions of the data object as the transmission bit rate expected to be supported by the client changes.
1 . An apparatus for adaptive streaming of a data object from a server toward a client via a Transmission Control Protocol (TCP) connection, the server having access to a plurality of versions of the data object having a respective plurality of encoding bit rates associated therewith, the apparatus comprising:
a processor and a memory, the processor configured to:
determine, from information associated with a TCP congestion control mechanism running on the server for the TCP connection, a transmission bit rate expected to be supported by the client for the TCP connection; and
select, based on the transmission bit rate expected to be supported by the client and the encoding bit rates associated with the versions of the data object accessible to the server, one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection.
2 . The apparatus of claim 1 , wherein the selected one of the versions of the data object is a first version of the data object, wherein the processor is configured to:
when the transmission bit rate expected to be supported by the client changes to a new transmission bit rate expected to be supported by the client, switch from selecting the first version of the data object to selecting a second version of the data object from the plurality of versions of the data object, wherein the encoding bit rate of the second version of the data object is compatible with the new transmission bit rate expected to be supported by the client.
3 . The apparatus of claim 1 , wherein the processor is configured to determine the information associated with a TCP congestion control mechanism running on the server for the TCP connection from a TCP stack on the server.
4 . The apparatus of claim 1 , wherein the information associated with the TCP congestion control mechanism running on the server for the TCP connection comprises a current transmission bit rate of the TCP connection on the server.
5 . The apparatus of claim 4 , wherein the transmission bit rate expected to be supported by the client for the TCP connection is determined as the current transmission bit rate of the TCP connection on the server.
6 . The apparatus of claim 4 , wherein the information associated with the TCP congestion control mechanism running on the server for the TCP connection comprises at least one additional parameter associated with the TCP connection.
7 . The apparatus of claim 6 , wherein the at least one additional parameter associated with the TCP connection comprises at least one of a peak transmission bit rate at which the data object is transmitted from the server toward the client via the TCP connection, a measure of packet loss for the TCP connection, an indication of intermittent packet loss for the TCP connection, and a round-trip time associated with the TCP connection.
8 . The apparatus of claim 6 , wherein the processor is configured to:
select one of the plurality of versions of the data object, based on the transmission bit rate expected to be supported by the client and the at least one additional parameter associated with the TCP connection.
9 . The apparatus of claim 1 , wherein the processor is configured to:
propagate the selected version of the data object toward the client.
10 . The apparatus of claim 1 , wherein the data object comprises video content.
11 . A method for adaptive streaming of a data object from a server toward a client via a Transmission Control Protocol (TCP) connection, the server having access to a plurality of versions of the data object having a respective plurality of encoding bit rates associated therewith, the method comprising:
using a processor and a memory for:
determining, from information associated with a TCP congestion control mechanism running on the server for the TCP connection, a transmission bit rate expected to be supported by the client for the TCP connection; and
selecting, based on the transmission bit rate expected to be supported by the client and the encoding bit rates associated with the versions of the data object accessible to the server, one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection.
12 . The method of claim 11 , wherein the selected one of the versions of the data object is a first version of the data object, the method further comprising:
when the transmission bit rate expected to be supported by the client changes to a new transmission bit rate expected to be supported by the client, switching from selecting the first version of the data object to selecting a second version of the data object from the plurality of versions of the data object, wherein the encoding bit rate of the second version of the data object is compatible with the new transmission bit rate expected to be supported by the client.
13 . The method of claim 11 , wherein the information associated with a TCP congestion control mechanism running on the server for the TCP connection is determined from a TCP stack on the server.
14 . The method of claim 11 , wherein the information associated with the TCP congestion control mechanism running on the server for the TCP connection comprises a current transmission bit rate of the TCP connection on the server.
15 . The method of claim 14 , wherein the transmission bit rate expected to be supported by the client for the TCP connection is determined as the current transmission bit rate of the TCP connection on the server.
16 . The method of claim 14 , wherein the information associated with the TCP congestion control mechanism running on the server for the TCP connection comprises at least one additional parameter associated with the TCP connection.
17 . The method of claim 16 , wherein the at least one additional parameter associated with the TCP connection comprises at least one of a peak transmission bit rate at which the data object is transmitted from the server toward the client via the TCP connection, a measure of packet loss for the TCP connection, an indication of intermittent packet loss for the TCP connection, and a round-trip time associated with the TCP connection.
18 . The method of claim 16 , further comprising:
selecting one of the plurality of versions of the data object, based on the transmission bit rate expected to be supported by the client and the at least one additional parameter associated with the TCP connection.
19 . The method of claim 11 , further comprising:
propagating the selected version of the data object toward the client.
20 . The method of claim 11 , wherein the data object comprises video content.
21 . A computer-readable storage medium storing instructions which, when executed by a computer, cause the computer to perform a method for adaptive streaming of a data object from a server toward a client via a Transmission Control Protocol (TCP) connection, the server having access to a plurality of versions of the data object having a respective plurality of encoding bit rates associated therewith, the method comprising:
determining, from information associated with a TCP congestion control mechanism running on the server for the TCP connection, a transmission bit rate expected to be supported by the client for the TCP connection; and
selecting, based on the transmission bit rate expected to be supported by the client and the encoding bit rates associated with the versions of the data object accessible to the server, one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection.
22 . An apparatus for adaptive streaming of a data object from a server toward a client via a Transmission Control Protocol (TCP) connection, the server having access to a plurality of versions of the data object having a respective plurality of encoding bit rates associated therewith, the apparatus comprising:
a processor and a memory, the processor configured to:
determine, from information associated with a TCP congestion control mechanism running on the server for the TCP connection, a transmission bit rate expected to be supported by the client for the TCP connection; and
switch, based on the transmission bit rate expected to be supported by the client and the encoding bit rates associated with the versions of the data object accessible to the server, from selecting a first one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection to selecting a second one of the plurality of versions of the data object for propagation from the server toward the client via the TCP connection.