VIDEO CACHING IN A WIRELESS COMMUNICATION NETWORK

• US 20120147865A1
• Filed: 12/14/2010
• Published: 06/14/2012
• Est. Priority Date: 12/14/2010
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Pothula, Avinash, Ravindra, Guntur, Chintada, Suresh
• Granted Patent: US 8,681,758 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: G01C 21/3461 Preferred or disfavoured areas, e.g. dangerous zones, toll or emission zones, intersections, manoeuvre types, segments such as motorways, toll roads, ferries
• CPC Class Codes: H04L 45/122 by minimising distances, e.g. by selecting a route with minimum of number of hops
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

Video caching in a wireless communication network includes determining 300 starting and ending points of a route of a mobile device and a minimum length route therebetween 302. Intermediate access points are identified 304 along the route, and these points are polled 306 for their available bandwidth and memory. A streaming capacity is defined 308 of each access point. Access points are selected 310 having an additive streaming capacity greater or equal to a size of a video file for the mobile device, and a defined number of sequential blocks of the video file are sent 312 to each access point. Each access points then downloads 314 its blocks as the mobile device traverses a service area of that access point.

Claims

1. A method for video caching in a wireless communication network, the method comprising:

determining a starting point and an ending point of a path to be taken by a mobile device through a wireless local area network of access points, the path including a service area of a starting access point and a service area of an ending access point;

establishing a route with a minimum path length between the starting point and the ending point;

identifying service areas of intermediate access points along the route;

polling the access points along the route for their respective available bandwidth and amount of cache memory that is already being used out of its total available cache memory;

defining a streaming capacity of each access point;

selecting those access points having an additive streaming capacity that totals greater or equal to a size of a video file to be downloaded to the mobile device;

sending instructions to each access point from the selecting step to cache a defined number of sequential blocks of the video file; and

downloading the blocks from each access point to the mobile device as the mobile device traverses a service area of that access point.

2. The method of claim 1, wherein establishing includes tracking a path traversed by the mobile device during downloading of the video.

3. The method of claim 1, wherein selecting includes listing the access points in order of decreasing ratio of available bandwidth to the amount of cache memory that is already being used out of its total available cache memory, and adding the streaming capacities of each access point in the list in succession until the additive streaming capacity totals greater or equal to a size of a video file to be downloaded to the mobile device.

4. The method of claim 3, wherein selecting includes ordering the selected access points in the total according to their locations on the route.

5. The method of claim 1, wherein in the defining step the streaming capacity of each access point equals its available bandwidth times a predicted amount of time that the mobile device will spend within the service area of that access point along the route.

6. The method of claim 1, wherein the instructions in the sending step divide sequential blocks of the video file among the access points of the selecting step in accordance with their location on the route and their ratio of available streaming capacity to their amount of cache memory that is already being used out of its total available cache memory.

7. The method of claim 6, wherein the access points of the selecting step each receive a portion of the video file, and further comprising:

scoring each block in the portion in accordance to a number of times that each block has been accessed, and

assigning a score to all blocks in the portion equal to that of the most accessed video block in the portion.

8. The method of claim 7, further comprising replacing cached video blocks dependent on their score, wherein higher scored blocks are cached longer than lower scored block.

9. A network entity operable for video caching in a wireless communication network, the network entity comprising:

a transceiver; and

a processor coupled to the transceiver, the processor operable to determine a starting point and an ending point of a path to be taken by a mobile device through the wireless communication network of access points, the path including a service area of a starting access point and a service area of an ending access point, the processor operable to establish a route with a minimum path length between the starting point and the ending point, and identify service areas of intermediate access points along the route, the processor operable to poll the access points along the route for their respective available bandwidth and amount of cache memory that is already being used out of its total available cache memory, and define a streaming capacity of each access point, wherein the processor selects those access points having an additive streaming capacity totaling greater or equal to a size of a video file to be downloaded to the mobile device, the processor directs the transceiver to send instructions to each access point to cache a defined number of sequential blocks of the video file such that these blocks can be downloaded from each access points as the mobile device traverses a service area of that access point.

10. The entity of claim 9, wherein the entity is a switch operable to control a wireless local area network incorporating the access points.

11. The entity of claim 9, wherein the processor is operable to track a path traversed by the mobile device during downloading of the video.

12. The entity of claim 9, wherein the processor is operable to list the access points in order of decreasing ratio of available bandwidth to the amount of cache memory that is already being used out of its total available cache memory, and add the streaming capacities of each access point in the list in succession until the additive streaming capacity totals greater or equal to a size of a video file to be downloaded to the mobile device.

13. The entity of claim 12, wherein the processor is operable to order the selected access points in the total according to their locations on the route.

14. The entity of claim 9, wherein the instructions operate to divide sequential blocks of the video file among the access points in accordance with their available streaming capacity to their available cache memory.

15. The entity of claim 9, wherein the streaming capacity of each access point equals its available bandwidth times a predicted amount of time that the mobile device will spend within the service area of that access point along the route.

16. The entity of claim 9, wherein the access points each receive a portion of the video file, and wherein the processor scores each block in the portion in accordance to a number of times that each block has been accessed, and assigns a score to all blocks in the portion equal to that of the most accessed video block in the portion.

17. The entity of claim 16, wherein the access points replace cached video blocks dependent on their score, wherein higher scored blocks are cached longer than lower scored block.