Method and apparatus for distributed transmission of real-time multimedia ...

United States Patent [w]

Chaddha et al.

US006151632A [ii] Patent Number: 6,151,632 [45] Date of Patent: Nov. 21,2000

[54] METHOD AND APPARATUS FOR

DISTRIBUTED TRANSMISSION OF REAL-
TIME MULTIMEDIA INFORMATION

[75] Inventors: Navin Chaddha, Sunnyvale; David del Val, Mountain View; Srinivas Prasad Vellanki, Milpitas, all of Calif.

[73] Assignee: Microsoft Corporation, Redmond, Wash.

[21] Appl. No.: 08/865,788 [22] Filed: May 30, 1997

Related U.S. Application Data

[63]

[51] [52] [58]

[56]

Continuation-in-part of application No. 08/818,127, Mar. 14, 1997.

Int. CI. G06F 15/16

U.S. CI 709/231; 709/208; 348/384

Field of Search 709/208, 216,

709/217, 218, 231, 219; 395/800.31; 340/825, 855.7; 348/384, 385, 388; 370/468

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OTHER PUBLICATIONS

Chaddha, N., et al., "An end to end software only scalable video delivery system", Proceedings Networks and Operating System Support for Digital Audio and Video, pp. 130-141, (Apr. 21, 1995).

Primary Examiner—Zarni Maung

Assistant Examiner—-Jason D. Cardone

Attorney, Agent, or Firm—Schwegman, Lundberg,

Woessner & Kluth, PA.

[57] ABSTRACT

A method and apparatus for delivering real-time multimedia information to clients via a distributed network is provided. The method and apparatus includes a LiveStation for encoding the real-time multimedia information into a number of different bandwidth points, and associated indexes, each bandwidth point for transmission over data channels of a particular bandwidth. The bandwidth points and indexes are provided to a recaster server to push the bandwidth points and indexes in parallel to secondary servers. The secondary servers then provide clients with compressed multimedia information according to the type of data channel used for connection. Parallel transmission of multiple bandwidth points and indexes allows the secondary servers to dynamically switch bandwidth points if data channels to clients change during transmission. Protocol between the LiveStation and a Recaster server, and between Recaster servers and secondary servers, is provided to allow configuration and transmission of real-time multimedia information to be controlled over a computer network from a single point.

57 Claims, 4 Drawing Sheets