Map Tile Pre-fetching for Mobile Route Rendering

Solution Overview

Problem

Existing map rendering systems face inefficiencies in data management and retrieval, particularly in mobile devices, due to the large amounts of data required for mapping applications, which can lead to prolonged download times and high bandwidth and processor usage, especially when intermittent connections and limited computing resources are involved.

Innovation Solution

A method for pre-fetching map data by determining specific tile radii for an origin, destination, and points along a route, allowing for the storage of pre-fetch map data tiles in local memory, enabling efficient display and reducing the need for continuous database access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all map data tiles are downloaded to the mobile device, then the map display application can buffer map data for display, but the download time increases and buffer memory usage increases

Engineering Contradiction:

Improvemap data availabilityVSAvoiddownload time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts only the necessary map data tiles from the complete map database by calculating tile radii around the origin, destination, and intermediate points along the route. This selective extraction approach downloads only the subset of map data needed for the specific route display, eliminating unnecessary data transfer while ensuring all required map areas are available.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary calculation of tile radii and identification of required map data tiles before the actual download process. By pre-determining the exact scope of map data needed based on route geometry and display requirements, the system prepares an optimized download list that minimizes data transfer time while guaranteeing data availability for the map display application.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a large number of map data tiles are provided at any particular time, then the mobile device can buffer map data for display, but the buffer memory usage increases

Engineering Contradiction:

Improvemap data availabilityVSAvoidbuffer memory usage

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts only the necessary map data tiles from the complete map database by calculating tile radii around the origin, destination, and intermediate points along the route. This selective extraction approach downloads only the subset of map data needed for the specific route display, eliminating unnecessary data transfer while ensuring all required map areas are available.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If map data is downloaded through intermittent wireless connections, then mobile devices can access map databases, but the download efficiency decreases

Engineering Contradiction:

Improveconnection flexibilityVSAvoiddownload efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent performs preliminary calculation of tile radii and identification of required map data tiles before the actual download process. By pre-determining the exact scope of map data needed based on route geometry and display requirements, the system prepares an optimized download list that minimizes data transfer time while guaranteeing data availability for the map display application.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2791821B8Pre-fetching map tile data along a route

Publication Date: 2017.11.29 GOOGLE LLC

AI summary

The present application describes techniques for fetching map data as a selected subset of entire map data available by selecting map data tiles corresponding to an area that encompasses a route. An amount of map data accessed may be adjusted based on a priority assigned to areas or points along the route. A sequence of map data may be accessed based on a priority assigned to sets of map data.