EP0714066A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Communications system and method including energy-efficient caching for mobile computing
Assignee: International Business Machines Corp
•
Filing: 1995-09-15
•
Granted: —
•
Expires: 2015-09-15
Abstract
Abstract A communications system and method include an efficient cache invalidation technique which allows a computer to relocate and to disconnect without informing the server. The server partitions the entire database into a number of groups. The server also dynamically identifies recently updated objects in a group and excludes them from the group when checking the validity of the group. If these objects have already been included in the most recent invalidation broadcast, the remote computer can invalidate them in its cache before checking the group validity with the server. With the recently updated objects excluded from a group, the server can conclude that the cold objects in the group can be retained in the cache, and validate the rest of the group.
Inventors
- 👤 Ming-Syan Chen
- 👤 Kun-Lung Wu
- 👤 Philip Shi-Lung Yu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 08:00
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/08; G06F12/0802; G06F12/0806; G06F12/0813; G06F16/00; G06F16/10; G06F16/17; G06F16/172; H; H04; H04L; H04L9/00; H04L9/40; Y; Y02; Y02D; Y02D10/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
108 words
A method of reducing overhead in a communications system having one or more remote units in communications with one or more servers, where said remote units are adapted to operate in a disconnected mode for a period of time, comprising the steps of: combining data objects stored in said one or more servers into one or more groups; broadcasting invalidation reports by one or more of said servers to one or more remote computers; dynamically excluding by said one or more servers one or more most recently updated objects from a group;and efficiently checking at said one or more servers a group validity without object by object comparisons.
Claim 2
Dependent Claim
50 words
A method of reducing overhead in a communications system according to Claim 1, wherein said broadcasting step further comprises periodically broadcasting by one of said servers to said one or more remote computers an invalidation report containing one or more objects updated during a most recent plurality of broadcast intervals.
Claim 3
Dependent Claim
39 words
A method of reducing overhead in a communications system according to Claim 1 or 2, further comprising the step of: invalidating contents of caches in said one or more remote computers based on information contained in said invalidation reports.
Claim 4
Independent Claim
52 words
A method of reducing overhead in a communications system according to one of claims 1 to 3, further comprising the step of: maintaining at said one or more servers a latest update time of a group and a number of objects in a group which are updated during a predetermined time interval.
Claim 5
Independent Claim
62 words
A method of reducing overhead in a communications system according to one of claims 1 to 4, further comprising the steps of: waiting for a next invalidation broadcast to invalidate cache entries in one of said remote computers; and sending a time identifier of a last invalidation report received by said remote computer before a most recent disconnection of said remote computer.
Claim 6
Independent Claim
46 words
A method of reducing overhead in a communications system according to one of claims 1 to 5, further comprising the step of: determining at said one or more servers a validity of a group which excludes one or more objects updated during a predetermined broadcast interval.
Claim 7
Dependent Claim
74 words
A data communications system comprising: a communications network; one or more servers connected to said communications network; and one or more remote computers adapted to operate in a disconnected mode for a period of time, and adapted to operate in communication with said one or more servers, each of said remote computers comprising means responsive to a broadcast invalidation report from one of said servers for invalidating cache contents identified in said invalidation report.
Claim 8
Dependent Claim
51 words
A data communications system according to Claim 7 further comprising: means in said one or more servers for dynamically excluding one or more most recently updated objects from a group of objects; and means for efficiently checking by said one or more servers a group validity without object by object comparisons.
Claim 9
Dependent Claim
48 words
A data communications system according to Claim 7 or 8, further comprising: means for maintaining at said one or more servers a latest update time of each group of objects and a number of objects in each said group that have been updated during a predetermined time interval.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.