Audio server system for an unreliable network

• US 6,118,790 A
• Filed: 06/19/1996
• Issued: 09/12/2000
• Est. Priority Date: 06/19/1996
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bolosky, William J., VanAntwerp, Mark D., Bernet, Yoram, Levi, Steven P.
• Primary Examiner(s): VU, HUY DUY
• Application Number:
  US08/667,095
• Time in Patent Office: 1,546 Days
• Field of Search: 370/352, 370/353, 370/354, 370/355, 370/356, 370/468, 370/470, 370/473, 370/465, 348/7, 348/13, 709/213, 709/214, 709/215, 709/216
• US Class Current: 370/468
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

An audio server system is provided that sends audio sequences or mixed audio and still-picture sequences to subscribers at their request. To be used as an audio server system in the Internet environment, the audio server system must overcome the Internet'"'"'s excessive loss of packets. The audio server system overcomes this problem by allowing for pre-specified packet sizes and pre-specified data rates. By allowing for pre-specified packet sizes, the audio server system can utilize an error correction scheme, such as parity encoding, so as to reduce the effects of the Internet'"'"'s excessive loss of packets. Pre-specified data rates are provided by the audio server system so as to ensure that audio sequences or mixed audio sequences are not played faster than intended, which may lead to an increase in system data loss.

Claims

1. A method in a continuous media server system for sending an audio sequence to a subscriber in such a manner as to reduce transmission errors, the continuous media server system having a plurality of storage devices, the method comprising the steps of:

striping the audio sequence as a set of blocks across the plurality of storage devices;

establishing a length of time available for sending the blocks of the audio sequence to the subscriber via a transmission medium;

establishing that the audio sequence can be sent to the subscriber via the transmission medium in a minimum length of time; and

effectively sending the blocks of the audio sequence from the storage devices to the subscriber via the transmission medium over substantially the entire available length of time, so that the audio sequence is sent during a length of time longer than the minimum length of time necessary for the transmission medium.

2. The method of claim 1 wherein the available length of time is an amount of time needed by the subscriber to play the audio sequence.

3. The method of claim 1, further including the step of encoding the audio sequence in an error-tolerant format before striping the audio sequence.

4. The method of claim 1, further including the steps of:

striping a second audio sequence across the plurality of storage devices;

determining that the second audio sequence can be sent to the subscriber via the transmission medium in a second length of time shorter than the available length of time, the second length of time distinct from the length of time in which the audio sequence can be sent to the subscriber via the transmission medium; and

sending the second audio sequence from the storage devices to the subscriber via the transmission medium during the entire available length of time.

5. The method of claim 1 wherein the continuous media server system is connected to the subscriber via an Internet and wherein the step of sending the audio sequence includes sending the audio sequence to the subscriber via the Internet.

6. The method of claim 1 wherein the continuous media server system has a still picture and wherein the step of sending the audio sequence includes sending the still picture to the subscriber.

7. A method in a continuous media server system having a plurality of storage devices for sending an audio sequence to a client, comprising the steps of:

striping the audio sequence across the plurality of storage devices;

receiving from the client an indication of a length of time over which the audio sequence is to be sent to the client;

determining that the audio sequence can be sent to the client in a length of time shorter than the indicated length of time; and

sending the audio sequence from the storage devices to the client over substantially the indicated length of time.

8. A computer-readable medium whose contents cause a continuous media server system having a plurality of storage devices to send a first audio sequence to a first subscriber and a second audio sequence to a second subscriber, by performing the steps of:

striping the first audio sequence across the plurality of storage devices;

receiving a first request from the first subscriber for the first audio sequence;

determining a first predetermined amount of time over which the first audio sequence is to be sent, the first amount of time longer than a minimum amount of time needed to send the first audio sequence to the first subscriber;

sending the first audio sequence from the storage devices to the first subscriber over substantially the first amount of time;

striping the second audio sequence across the plurality of storage devices;

receiving a second request from the second subscriber for the second audio sequence;

determining a second predetermined amount of time over which the second audio sequence is to be sent, the second amount of time longer than a minimum amount of time needed to send the second audio sequence to the second subscriber; and

sending the second audio sequence from the storage devices to the second subscriber over substantially the second amount of time.

9. A continuous media server system comprising:

a plurality of storage devices for storing an audio sequence; and

a server connected to a packet switched network to be used for sending the audio sequence to a subscriber as a plurality of packets, the server further comprising;

a first component for striping the audio sequence across the storage devices;

a second component for determining a length of time available for sending the striped audio sequence to the subscriber that is greater than a minimum amount of time needed to send the striped audio sequence, for receiving a packet size specifying a maximum amount of data in each packet, and for receiving a request from the subscriber for the audio sequence; and

a third component for dividing the striped audio sequence into the packets such that each packet contains an amount of data equivalent to or less than the packet size, and for sending the packets via the packet switched network to the subscriber over substantially the determined length of time.

10. The continuous media server system of claim 9 wherein a still picture is stored and sent with the striped audio sequence.

11. The continuous media server system of claim 9 wherein the packet switched network is an Internet.

12. The continuous media server system of claim 9 wherein the first component encodes the audio sequence using a parity encoding scheme before striping the audio sequence.