Physical layer caching for flexible MIMO cooperation in wireless networks

Patent metadata

Field	Value
Publication number	US-10129356-B2
Application number	US-201414542465-A
Country	US
Kind code	B2
Filing date	Nov 14, 2014
Priority date	Nov 15, 2013
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Cooperative physical layer caching systems for base stations are described herein. Base stations include cache memories that store portions of content. Base stations receive requests for content files from mobile devices. Cooperative physical layer caching systems can determine contents of the cache memories and can coordinate physical transmissions of the content files based on the contents of the cache memories.

First claim

What is claimed is:

1. A system, comprising:
a processor, coupled to a memory, that executes or facilitates execution of executable components stored at least partly in the memory, the executable components comprising:
a caching control component configured to:
select content files for storage in a first cache of a first base station device of a network and a second cache of a second base station device of the network, wherein respective amounts of the content files to store are based on an evaluation of data describing respective popularity metrics of the content files,
divide the content files into respective segments,
generate first data representing first portions of the respective segments and second data representing second portions of the respective segments of the content files, wherein the first data comprises a first set of maximum distance separable (MDS) encoded parity bits and the second data comprises a second set of MDS encoded parity bits, and
store the first data representing first portions of the respective segments in the first cache of the first base station and the second cache of the second base station and the second data representing second portions of the respective segments in a content server, wherein the first portions and the second portions are different portions and are stored as MDS-coded bits; and

a coordination component configured to:
receive, from a first mobile device, a first request to access a first segment of a first content file of the content files, and, from a second mobile device, a second request to access a second segment of a second content file of the content files, and
select a cooperative transmission mode or an interference transmission mode based on a first status of the first request and a second status of the second request,
wherein during the cooperative transmission mode, the first base station device and the second base station device perform cooperatively and spatially multiplexed transmissions of first cached MDS-coded bits from a set of cached MDS-coded bits of the first segment in response to the first request and second cached MDS-coded bits from a set of cached MDS-coded bits of the second segment in response to the second request, wherein an alignment of the first cached MDS-coded bits and the second cached MDS-coded bits increases a multiple-input multiple-output cooperation probability,
and wherein during the interference transmission mode, the first base station device transmits a first set of un-cached MDS-coded bits of the first segment, obtained from the content server, in response to the first request and the second base station transmits a second set of un-cached MDS-coded bits, obtained from the content server, in response to the second request, without a cooperation between the first base station and the second base station.

2. The system of claim 1 , wherein the caching control component is further configured to:
determine a first size of the first data and a second size of the second data based on at least one of a popularity metric of the content file or a size of the first cache and the second cache.

3. The system of claim 2 , wherein the caching control component is further configured to:
alter data describing the respective popularity metrics of the content files based on an updated set of data describing the respective popularity metrics of the content files.

4. The system of claim 1 , wherein the coordination component is further configured to:
based on a first determination that the first set of cached MDS-coded bits and the second set of cached MDS-coded bits have not been completely transmitted in response to the first request and the second request, select the cooperative transmission mode; and,
based on a second determination that the first set of cached MDS-coded bits and the second set of cached MDS-coded bits have been completely transmitted in response to the first request and the second request, select the interference transmission mode.

5. The system of claim 4 , wherein the coordination component is further configured to:
select transmission paths and a number of data streams to be spatially multiplexed by the first base station device and the second base station device, in accordance with the respective contents of the first cache and the second cache with respect to the first content file associated with the first request and the second content file associated with the second request, of signals associated with the first request to access the first segment, and other signals associated with the second request to access the second segment.

6. The system of claim 5 , wherein the coordination component is further configured to:
select the transmission paths based on a first performance criterion of the first base station device and a second performance criterion of the second base station device.

7. The system of claim 5 , wherein the coordination component is further configured to:
select the transmission paths based on characteristics of a first connection of the first base station device and a second connection of the second base station device.

8. The system of claim 1 , wherein the coordination component is further configured to:
select the first base station device based on a first determination that the first data representing the first portions of the respective segments in the first cache of the first base station comprises first request data associated with the first request to access the first segment of the first content file of the content files, wherein the first mobile device associated with the first request to access the first segment is operatively coupled to the first base station device; and
select the second base station device based on a second determination that the second data representing the second portions of the respective segments in the second cache of the second base station device comprises second request data associated with the second request to access the second segment of the second content file of the content files, wherein a coverage area of the second base station device serves a location of the first mobile device and the first mobile device is not operatively coupled to the second base station device.

9. The system of claim 8 , wherein the coordination component is further configured to:
in response to determining the first cache and the second cache comprise the first request data and the second request data, instruct the first base station device and the second base station device to transmit data to the first mobile device and the second mobile device, wherein the first base station device does not communicate with a third mobile device attached to the second base station device.

10. A method, comprising:
evaluating, by a system comprising a processing device, statistic data representing a statistic associated with access requests for content files;
identifying first segments of the content files for storage in a first cache of a first base station device of a communications network and in a second cache of a second base station device of the communications network and second segments of the content files for storage in a content server, wherein the communications network comprises a group of base station devices including the first base station device and the second base station device;
generating a first set of encoded data that represents first portions of the first segments of the content files and a second set of encoded data that represents second portions of the second segments of the content files, wherein the generating comprises using a maximum distance separable (MDS) coding process;
storing the first set of encoded data in the first cache of th

Assignees

• Univ Hong Kong Sci & Tech

Inventors

• Lau Vincent Kin Nang
• Liu An

Classifications

• H04L67/2842 Primary

  Electricity · mapped topic

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04L67/568 Primary

  Storing data temporarily at an intermediate stage, e.g. caching · CPC title