INTELLIGENT CACHE MANAGEMENT PROTOCOL FOR VEHICULAR NETWORKS

• US 20120151073A1
• Filed: 12/08/2010
• Published: 06/14/2012
• Est. Priority Date: 12/08/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Bai, Fan, Grimm, Donald K.
• Granted Patent: US 8,676,920 B2
• Time in Patent Office: Days
• US Class Current: 709/228
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

A method and system for cooperatively caching digital content in a vehicle for sharing with other vehicles in a vehicle-to-vehicle network. A content utility value is assigned to each piece of digital content available on the network, where the utility value is a function of the popularity of the content, the freshness of the content, and the size of the content. Any piece of content with a sufficiently high content utility value is stored in a host vehicle'"'"'s collective cache, so that other vehicles may be able to retrieve it quickly on demand. The host vehicle may cache a particular piece of digital content even if the host vehicle is not interested in it. The host vehicle periodically re-computes the content utility value for all digital content in the vehicle'"'"'s cache to determine if any of the data should be evicted from the cache.

Claims

1. A method for managing digital content data in a vehicle'"'"'s cache, said method comprising:

providing a local cache and a collective cache in a host vehicle, where the local cache is used to store digital content data files that are of interest to occupants of the host vehicle, and the collective cache is used to store digital content data files for sharing with other vehicles;

establishing communication with another vehicle by the host vehicle, and receiving a digital content summary list from the other vehicle;

identifying a new piece of digital content from the summary list;

determining if the new piece of digital content is of interest to occupants of the host vehicle and, if the new piece of digital content is of interest to occupants of the host vehicle, requesting replication of the new piece of digital content, receiving the new piece of digital content from the other vehicle, and storing the new piece of digital content in the local cache;

calculating a content utility value for the new piece of digital content if it was not stored in the local cache, and comparing the content utility value to a storage threshold value;

determining if the content utility value for the new piece of digital content exceeds the storage threshold value; and

requesting replication of the new piece of digital content, receiving the new piece of digital content from the other vehicle, and storing the new piece of digital content in the collective cache, if the content utility value for the new piece of digital content exceeds the storage threshold value.

2. The method of claim 1 wherein establishing communication with another vehicle by the host vehicle includes using a vehicle-to-vehicle network.

3. The method of claim 2 wherein the vehicle-to-vehicle network uses one or more Dedicated Short Range Communications channels or Wireless Local Area Network communication channels.

4. The method of claim 1 wherein calculating a content utility value includes using an equation containing a popularity value, a freshness value, and a size value.

5. The method of claim 4 further comprising determining if a predetermined time interval has elapsed and, if the time interval has elapsed, incrementing the popularity value for each of the digital content data files which have been requested by another vehicle, decrementing the freshness value for each of the digital content data files, and re-computing the content utility value for each of the digital content data files in the collective cache.

6. The method of claim 5 further comprising evicting from the collective cache any of the digital content data files for which the content utility value after re-computing is less than an eviction threshold value.

7. The method of claim 4 wherein the popularity value, the freshness value, and the size value are received from the other vehicle.

8. The method of claim 1 wherein storing the new piece of digital content in the collective cache includes evicting from the collective cache any of the digital content data files necessary to make room in the collective cache for the new piece of digital content.

9. The method of claim 8 wherein evicting from the collective cache any of the digital content data files includes evicting the digital content data files with the lowest content utility value.

10. The method of claim 1 wherein determining if the content utility value for the new piece of digital content exceeds the storage threshold value includes dividing the content utility value by a version value.

11. The method of claim 10 further comprising incrementing the version value each time the new piece of digital content is replicated.

12. A method for managing digital content data in a vehicle'"'"'s cache, said method comprising:

providing a local cache and a collective cache in a host vehicle, where the local cache is used to store digital content data files that are of interest to occupants of the host vehicle, and the collective cache is used to store digital content data files for sharing with other vehicles;

establishing communication with another vehicle in a vehicle-to-vehicle network by the host vehicle, and receiving a digital content summary list from the other vehicle;

identifying a new piece of digital content from the summary list;

determining if the new piece of digital content is of interest to occupants of the host vehicle and, if the new piece of digital content is of interest to occupants of the host vehicle, requesting replication of the new piece of digital content, receiving the new piece of digital content from the other vehicle, and storing the new piece of digital content in the local cache;

calculating a content utility value for the new piece of digital content if it was not stored in the local cache, and comparing the content utility value to a storage threshold value, where the content utility value is calculated using an equation containing a popularity value, a freshness value, and a size value;

determining if the content utility value for the new piece of digital content exceeds the storage threshold value; and

requesting replication of the new piece of digital content, receiving the new piece of digital content from the other vehicle, and storing the new piece of digital content in the collective cache, if the content utility value for the new piece of digital content exceeds the storage threshold value.

13. The method of claim 12 further comprising determining if a predetermined time interval has elapsed and, if the time interval has elapsed, incrementing the popularity value for each of the digital content data files which have been requested by another vehicle, decrementing the freshness value for each of the digital content data files, re-computing the content utility value for each of the digital content data files in the collective cache, and evicting from the collective cache any of the digital content data files for which the content utility value after re-computing is less than an eviction threshold value.

14. The method of claim 12 wherein storing the new piece of digital content in the collective cache includes evicting from the collective cache any of the digital content data files necessary to make room in the collective cache for the new piece of digital content, where the digital content data files with the lowest content utility value are evicted.

15. The method of claim 12 wherein determining if the content utility value for the new piece of digital content exceeds the storage threshold value includes dividing the content utility value by a version value.

16. A cache management system for a host vehicle in a vehicle-to-vehicle network, said system comprising:

a local cache module for storing digital content data files that are of interest to occupants of the host vehicle;

a collective cache module for storing digital content data files for sharing with other vehicles in the vehicle-to-vehicle network; and

a processor configured to receive digital content summary lists from the other vehicles in the vehicle-to-vehicle network, identify new pieces of digital content from the summary lists, replicate and store in the local cache module any of the new pieces of digital content which are of interest to the occupants of the host vehicle, and replicate and store in the collective cache module any of the new pieces of digital content which are considered to be of interest to the other vehicles in the vehicle-to-vehicle network.

17. The cache management system of claim 16 wherein the processor is configured to compute a content utility value for each of the new pieces of digital content, compare the content utility value to a storage threshold value, and store in the collective cache the new pieces of digital content for which the content utility value exceeds the storage threshold value.

18. The cache management system of claim 17 wherein the content utility value is a function of a popularity value, a freshness value, and a size value for each of the new pieces of digital content.

19. The cache management system of claim 18 wherein the processor is configured to re-compute the content utility value for each of the digital content data files in the collective cache at a predefined time interval using updated values of the popularity value and the freshness value, and evict from the collective cache any of the digital content data files with a content utility value less than an eviction threshold value.

20. The cache management system of claim 16 wherein the vehicle-to-vehicle network uses one or more Dedicated Short Range Communications channels or Wireless Local Area Network communication channels.