Side Information Cache Synchronization Using Hierarchical Node Indices

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Solution Overview

Problem

Existing data compression systems for mobile communication devices lack a method to synchronize side information caches, which are crucial for improving compression performance by leveraging knowledge of previously communicated data.

Innovation Solution

A method and system for synchronizing side information caches by comparing hierarchical node indices between a mobile communication device and a server, identifying common side information, and creating a shared common hierarchical node index to enhance interactive compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If side information caches are maintained at both mobile device and server separately, then compression performance can be improved through local knowledge, but the caches become desynchronized leading to suboptimal compression ratios

Engineering Contradiction:
Improvecompression performanceVSAvoidcache coherence
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The side information cache is segmented into local device cache and server cache, with hierarchical node indices dividing the cache structure into manageable segments that can be independently maintained yet synchronized through selective comparison and update mechanisms

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A feedback mechanism is implemented where the mobile device sends its hierarchical node index to the server, the server compares it with its own index, identifies differences, and updates its cache accordingly, ensuring continuous synchronization and optimal compression performance across both locations

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If complete side information is transmitted between device and server, then cache synchronization is achieved, but communication bandwidth is consumed

Engineering Contradiction:
Improvecache coherenceVSAvoidbandwidth consumption
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

Only the necessary portion of side information (hierarchical node index) is extracted and transmitted for synchronization purposes, rather than transmitting complete cache contents, thereby reducing communication overhead while maintaining cache coherence

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Partial synchronization is performed by comparing and updating only the differential portions of caches based on hierarchical node index comparison, avoiding the excessive action of synchronizing entire caches and thus conserving bandwidth

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If grammar-based compression with shared caches is implemented, then compression ratios improve, but system complexity increases

Engineering Contradiction:
Improvecompression ratioVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The hierarchical node index structure serves multiple functions: it organizes the grammar-based compression cache, enables efficient comparison for synchronization, and provides a universal interface for both device and server to maintain coherence, thereby managing complexity while improving compression ratios

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2153611B1Synchronization of side information caches
Publication Date: 2013.03.27 BLACKBERRY LTD
  • EP2153611B1 patent drawingFigure 1
  • EP2153611B1 patent drawingFigure 2
  • EP2153611B1 patent drawingFigure 3

AI summary

In order to improve interactive compression using compression state information, the side information caches of communicating parties must be updated, or synchronized. The present invention is directed to a method of synchronizing side information databases within an interactive compression system comprising two communicating parties comprising the steps of transmitting, from the a first communicating party to the second communicating party, a device hierarchical node index; comparing the device hierarchical node index with a server hierarchical node index and then determining a shared hierarchical node index based on common entries in the two hierarchical node indexes.