CACHING IN MOBILE NETWORKS

• US 20130013726A1
• Filed: 03/25/2010
• Published: 01/10/2013
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Westberg, Lars, Arvidsson, Ake
• Granted Patent: US 8,880,636 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

A method for optimising the distribution of data objects between caches in a cache domain of a resource limited network. User requests for data objects are received at caches in the cache domain. A notification is sent from each cache at which a request received to a cache manager. The notification reports the user request and identifies the requested data object. At the cache manager, object information including the request frequency of each requested data object and the locations of the caches at which the requests were received are collated and stored, and objects for distribution within the cache domain are identified on the basis of the object information. Instructions are sent from the cache manager to the caches to distribute data objects stored in those caches between themselves. The data objects are distributed between the caches using transmission capacity of the network that would otherwise be unused.

Claims

1. A network element configured to act as a cache for sending cached data in a session to a mobile terminal in a packet data network, the network element being associated with a cache storage unit for storing data objects, the network element comprising:

a communications system for communication with other elements in the network;

a DPI or proxy agent configured to inspect packets from the terminal passing through the network element to determine if they include a request for a data object, determine whether the requested data object is stored in the cache storage unit and, if so, send the requested data object towards the terminal; and

an object agent configured to receive instructions from a cache manager controlling caches in a cache domain of the network, and in response to send data objects to other caches in the cache domain using transmission capacity that would otherwise remain unused.

2. The network element of claim 1, wherein the object agent is further configured to receive data objects not requested by the mobile terminal from other caches in the cache domain, and to store the received data objects in the cache storage unit.

3. The network element of claim 1, wherein the DPI or proxy agent is configured so that, if the requested data object is not stored in the cache storage unit, the request is passed towards an upstream network element or the cache manager and, when the requested data object passes through the network element when it is returned towards the terminal, it is saved in the cache storage unit.

4. The network element of claim 1, wherein the network element is a Radio Base Station.

5. The network element of claim 1, wherein the object agent is configured to use transmission capacity that would otherwise remain unused by sending data objects to other caches during off-peak data traffic periods.

6. The network element of claim 5, wherein the data objects sent to the other caches during off-peak data traffic periods are not high priority data objects, and are sent in response to instructions from the cache manager.

7. The network element of claim 1, wherein the object agent is further configured to send high priority data objects to other caches in the cache domain during peak periods in response to instructions from the cache manager.

8. The network element of claim 6, wherein high priority data objects are those requested by another mobile terminal through another cache.

9. The network element of claim 1, wherein the object agent is configured to capture each event of a request for a particular data object, and pass this information to the cache manager to assist in identifying which data objects should be distributed between caches.

10. The network element of claim 1, wherein the cache storage unit is included in the network element.

15. The cache manager of claim 9, further comprising:

a topology monitor for retrieving topology information about the topology of the cache domain; and

a topology database for storing said topology information;

wherein the object distributor is configured to make use of the topology information in the determination of how the objects should be distributed between the caches.

16. The cache manager of claim 15, wherein the topology information includes data relating to one or more of:

a topology structure of the cache domain;

bandwidth limitations of links between elements in the topology structure;

location of caches in the topology structure;

current loads sustained by the rinks between elements in the topology structure; and

transport types for data within the cache domain.

11. A cache manager for controlling the distribution of content stored in caches in a cache domain in a packet data network, the cache manager comprising:

an object monitor for receiving notifications from caches in the cache domain about data objects requested at those caches;

an object database for collating and storing object information about the requested data objects, the object information including information about the caches at which the data objects have been requested and frequency with which the requests have been made; and

an object distributor for identifying objects for distribution on the basis of the object information and instructing the caches in the cache domain to distribute data objects stored in those caches between themselves using transmission capacity of the network that would otherwise be unused.

12. The cache manager of claim 11, wherein the cache manager is a discrete entity and includes a communications system for communicating with elements in the network.

13. The cache manager of claim 12, wherein the cache manager is associated with one of the caches in the cache domain.

14. The cache manager of claim 11, wherein the functionality of the cache manager is distributed among network elements in the cache domain.

17. The cache manager of claim 11, further configured to control the distribution of the data objects between caches in the cache domain so that the cache domain functions as a large virtual cache.

18. The cache manager of claim 11, wherein the network is a mobile network.

19. The cache manager of claim 18, wherein the cache domain corresponds to a radio access network in the mobile network.

20. The cache manager of claim 11, wherein the object distributor is configured to instruct the caches in the cache domain to distribute high priority objects between themselves during peak periods.

21. A method for optimising the distribution of data objects between caches in a cache domain of a resource limited network, the method comprising:

receiving user requests for data objects at caches in the cache domain;

sending a notification from the cache at which a request is received to a cache manager reporting the user request and identifying the requested data object;

at the cache manager, collating and storing object information including the request frequency of each requested data object and the locations of the caches at which the requests were received;

at the cache manager, identifying objects for distribution within the cache domain on the basis of the object information;

sending instructions from the cache manager to the caches to distribute data objects stored in those caches between themselves; and

distributing the data objects between the caches using transmission capacity of the network that would otherwise be unused.

22. The method of claim 21, wherein functionality of the cache manager is distributed between network elements in the cache domain.

23. The method of claim 21, wherein the cache manager further takes into account one or more of the topology of the network, the priority of the requested data objects, and the frequency of requests for particular data objects when identifying the data objects for distribution.

24. The method of claim 21, wherein the network is a mobile network.

25. The method of claim 24, wherein the caches are associated with or part of Radio Base Stations.

26. The method of claim 21, wherein the data objects are distributed between the caches during off-peak periods.

27. The method of claim 21, further comprising:

labelling a data object as a high priority data object if it is not stored in the cache at which the user request for that data objects is received; and

sending instructions, from the cache manager to a cache at which the high priority data object is stored, to send the high priority data object to the cache at which the user request was received during a peak period.

28. A non transitory computer program product comprising code adapted to be executed on a network element associated with a cache storage unit in a resource limited network, the code operable to cause the network element to:

inspect packets, from a terminal in the network, passing through the network element;

determine if said packets include a request for a data object;

determine whether the requested data object is stored in the cache storage unit and, if so, send the requested object towards the terminal;

receive instructions from a cache manager controlling caches in a cache domain of the network to send data objects to other caches in the cache domain using transmission capacity that would otherwise remain unused; and

send the data objects in accordance with the received instructions.

29. A non-transitory computer program product comprising code adapted to be executed on a cache manager in a resource limited network, the code operable to cause the cache manager to:

retrieve notifications from caches in a cache domain controlled by the cache manager, the notifications including details of data objects recently requested at those caches;

collate and store object information about the requested data objects, the object information including the location and popularity of requested data objects;

identify objects for distribution on the basis of the object information; and

instruct the caches in the network to distribute data objects stored in those caches between themselves using transmission capacity of the network that would otherwise be unused.

30. (canceled)