Media streaming with high rate availability

Patent metadata

Field	Value
Publication number	US-9357432-B2
Application number	US-201414293136-A
Country	US
Kind code	B2
Filing date	Jun 2, 2014
Priority date	Jun 2, 2014
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A system and method for media streaming in a scenario where very high bitrate wireless service is available within a macro cell through small cells. When a mobile device is in a small cell, a base station may download the multimedia content onto the mobile device at the high bitrate instead of streaming the content at a low bitrate. The mobile device cannot misuse the content made available through the download because its ability to de-scramble the downloaded information is made time dependent by a two-stage scrambling process at the base station that keeps the information scrambled until it is ready to be consumed. The base station withholds from the mobile device information related to de-scrambling of the received content until the appropriate time. Such withheld information includes time-varying decryption keys, which control the timing of decryption and are supplied to the mobile device in a temporally sequential manner.

First claim

What is claimed is:

1. A method of delivering multimedia content to a mobile device operating in a macro cell in a cellular network that supports a first bitrate and a second bitrate for transmitting the multimedia content to the mobile device, wherein the method comprises performing the following using a network entity in the cellular network:
streaming the multimedia content to the mobile device at the first bitrate, wherein the first bitrate is available throughout the macro cell and wherein the second bitrate is available only over a small cell within the macro cell and is substantially higher than the first bitrate; and
upon detecting that the mobile device is present in the small cell, delivering the multimedia content to the mobile device at the second bitrate instead of streaming at the first bitrate.

2. The method of claim 1 , wherein delivering the multimedia content includes performing the following using the network entity:
downloading the multimedia content onto the mobile device at the second bitrate.

3. The method of claim 1 , wherein delivering the multimedia content includes performing the following using the network entity:
restricting the mobile device to consume delivered multimedia content as if the delivered multimedia content were streamed to the mobile device at the first bitrate.

4. The method of claim 3 , wherein restricting the mobile device includes performing the following using the network entity:
scrambling all messages in the delivered multimedia content in a manner similar to scrambling of messages in the multimedia content streamed at the first bitrate;
further scrambling all the messages in the delivered multimedia content using a time-varying cryptography scheme that is different from a cryptography scheme used for scrambling the multimedia content streamed at the first bitrate; and
temporally sequentially supplying a first plurality of time-varying decryption keys to the mobile device as part of the time-varying cryptography scheme, wherein each decryption key in the first plurality of time-varying decryption keys is configured to de-scramble only a key-specific portion of the messages in the delivered multimedia content and is supplied to the mobile device only when a time instance associated with that decryption key occurs, thereby restricting the mobile device to consume delivered multimedia content as if the delivered multimedia content were streamed to the mobile device at the first bitrate.

5. The method of claim 4 , wherein temporally sequentially supplying the first plurality of time-varying decryption keys includes performing the following using the network entity:
when the multimedia content is delivered to the mobile device at a time instance “t”, supplying a first decryption key in the first plurality of time-varying decryption keys to the mobile device along with the delivered multimedia content, wherein the first decryption key is associated with the time instance “t” and is configured to enable the mobile device to de-scramble only a first message that is associated with the time instance “t” in the delivered multimedia content; and
after the multimedia content is delivered to the mobile device at the time instance “t”:
supplying a second decryption key in the first plurality of time-varying decryption keys at a time instance “t+1,” wherein the second decryption key is configured to enable the mobile device to de-scramble only a second message that is associated with the time instance “t+1” in the delivered multimedia content, and
temporally sequentially supplying subsequent decryption keys at key-specific time instances “t+2” and beyond until all remaining decryption keys in the plurality of time-varying decryption keys are sent to the mobile device to enable the mobile device to de-scramble only those key-specific messages in the delivered multimedia content that are associated with key-specific time instances.

6. The method of claim 5 , wherein each of the second and subsequent decryption keys is supplied to the mobile device regardless of whether additional multimedia content is delivered to the mobile device at time instances “t+1” and beyond.

7. The method of claim 4 , wherein at least one of the first plurality of time-varying decryption keys is unique to the mobile device.

8. The method of claim 4 , wherein the cryptography scheme used for scrambling the content streamed at the first bitrate is a public-key cryptography scheme, and wherein the time-varying cryptography scheme used for scrambling the multimedia content delivered at the second bitrate is a private-key cryptography scheme.

9. The method of claim 4 , further comprising performing the following using the network entity:
scrambling each decryption key in the first plurality of time-varying decryption keys using a public-key cryptography scheme before temporally sequentially supplying the first plurality of time-varying decryption keys to the mobile device.

10. The method of claim 4 , further comprising performing the following using the network entity:
upon detecting that the mobile device is no longer present in the small cell:
ceasing the delivery of the multimedia content to the mobile device at the second bitrate;
despite ceasing the delivery of the multimedia content to the mobile device at the second bitrate, continuing to temporally sequentially supply to the mobile device any time-varying decryption keys in the first plurality of time-varying decryption keys that are still pending to be sent to the mobile device; and
reverting to the streaming at the first bitrate for subsequent transmission of the multimedia content to the mobile device.

11. The method of claim 10 , wherein reverting to the streaming at the first bitrate includes performing the following using the network entity:
commencing the streaming-based subsequent transmission of the multimedia content to the mobile device after the delivered multimedia content is substantially consumed in the mobile device.

12. The method of claim 11 , wherein commencing the streaming-based subsequent transmission includes performing the following using the network entity:
determining that the delivered multimedia content is substantially consumed in the mobile device based on communication with the mobile device.

13. The method of claim 10 , further comprising performing the following using the network entity:
using the time-varying cryptography scheme, scrambling new messages to be sent to the mobile device as part of the subsequent transmission of the multimedia content through streaming at the first bitrate, wherein the time-varying cryptography scheme is used in addition to any cryptography scheme used for scrambling the new messages to be sent to the mobile device through streaming at the first bitrate; and
temporally sequentially supplying a second plurality of time-varying decryption keys to the mobile device as part of the time-varying cryptography scheme, wherein each decryption key in the second plurality of time-varying decryption keys is configured to de-scramble only a key-specific portion of the new messages in the subsequent transmission of the multimedia content and is supplied to the mobile device only when a time instance associated with that decryption key occurs.

14. The method of claim 4 , wherein at least two decryption keys in the first plurality of time-varying decryption keys are identical.

15. The method of claim 4 , further comprising performing the following using the network entity:
instructing the mobile device to use a decryption key associated with a time instance “t” in the first plurality o

Assignees

• Ericsson Telefon Ab L M

Inventors

• Khayrallah Ali S

Classifications

• H04L65/1083

  In-session procedures · CPC title

• H04W28/0268 Primary

  using specific QoS parameters for wireless networks, e.g. QoS class identifier [QCI] or guaranteed bit rate [GBR] (negotiating SLA or negotiating QoS H04W28/24) · CPC title

• H04L9/16 Primary

  the keys or algorithms being changed during operation · CPC title

• H04W36/00

  Hand-off or reselection arrangements · CPC title

• H04L65/60

  Network streaming of media packets · CPC title