摘要:
A method for performing a soft-handoff in a mobile streaming media system, and a method for performing a hard-handoff in a mobile streaming media system are is disclosed. In the soft-handoff embodiment, the present invention detects that a channel quality between a mobile client and a first base station remains above a drop threshold and that a channel quality between the mobile client and a second base station increases from below to above an add threshold. The present embodiment then sends a first multiple description bitstream from the first base station to the mobile client and sends a complementary second multiple description bitstream from the second base station to the mobile client. This method thereby provides improved utilization of wireless bandwidth during soft-handoffs, in contrast to conventional systems where the same bitstream is transmitted from each base station. In both the cases of soft-handoffs and hard-handoffs, when a mobile client enters a cell whose base station has no free capacity, the base station may prevent call dropping by reducing the number of descriptions being served to the existing clients and thereby providing capacity (at least one description) for the new client. These methods provide improved utilization of wireless bandwidth during soft-handoffs, and reduced probability of service disruption during both soft-handoffs and hard-handoffs.
摘要:
A method for handing off to a second server, in either a fixed or mobile streaming media system, a multiple description streaming session between a first server and either a fixed or mobile client. In one embodiment, the present invention recites selecting a second server to receive a handoff of a multiple description streaming media session between the first server and the client. In this embodiment, the multiple description streaming media session is comprised of a first multiple description bitstream and a second multiple description bitstream. The present embodiment further recites receiving at the second server, the second multiple description bitstream for streaming to the client. This embodiment further recites sending the second multiple description bitstream from the second server to the client.
摘要:
A method for assigning servers to provide multiple description bitstreams to a mobile client (in a mobile client environment) or to a fixed client (in a fixed client environment). In one embodiment, the present invention, upon receiving a request from a mobile client to have media data streamed thereto, analyzes a plurality of servers to determine a first candidate server for providing a first multiple description bitstream to the base station along a first path. The present method also determines a second candidate server for providing a second multiple description bitstream to the base station along a second path. The present method then sends a request to the first candidate server to provide the first multiple description bitstream to a mobile client through a base station along the first path, and also sends a request to the second candidate server to provide the second multiple description bitstream to the mobile client through the same base station along a second path. In another embodiment, there are two separate paths from two separate servers to two separate base stations and then from each base station there is a separate path to the mobile client. In still another embodiment, there are two paths from a single server to two separate base stations and then from each base station there is a separate path to the mobile client. In one fixed client embodiment, the present invention is able to assign a plurality of servers to provide a plurality of MD bitstreams to the fixed client.