APPARATUS AND METHODS FOR REDUCING DATA TRANSMISSION IN WIRELESS CLIENT-SERVER NAVIGATION SYSTEMS
First Claim
1. A method of reducing the amount of data transmitted in a wireless client-server navigation system of the type wherein mobile clients request and receive guidance from a central server accessing databases of geographical information, the method comprising the steps of:
- transmitting data from a mobile client to a central server explicitly or implicitly requesting the transmission of map data from the central server;
transmitting, from the mobile client to the central server, a summary of map data already present at the mobile client;
comparing, at the central server, the requested map data to the map data already present at the mobile client; and
transmitting, from the central server to the mobile client, map data requested by the client, but excluding map data determined by the server to be already present in the client based on the previously transmitted summary information.
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0 Petitions
Accused Products
Abstract
Methods and apparatus reduce data transmission in a wireless client-server navigation system. Data is transmitted from a mobile client to a central server explicitly or implicitly requesting the transmission of map data from the central server. At the same time or previously, the mobile client forwards to the central server, a summary of map data already present at the mobile client. The central server compares the received request to the map data already present at the mobile client based upon the information received from the mobile client, and if there is overlap, the central server downloads the map data requested by the client, but excludes map data determined by the server to be already present in the client based on the previously transmitted summary information, thereby reducing data transmission requirements. The summary of map data present in the client may be transmitted to the central server in a reduced-data format. The reduced-data format may comprise designators associated with regions such as tiles into which a map has been partitioned. System-level aspects are additionally disclosed.
25 Citations
21 Claims
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1. A method of reducing the amount of data transmitted in a wireless client-server navigation system of the type wherein mobile clients request and receive guidance from a central server accessing databases of geographical information, the method comprising the steps of:
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transmitting data from a mobile client to a central server explicitly or implicitly requesting the transmission of map data from the central server; transmitting, from the mobile client to the central server, a summary of map data already present at the mobile client; comparing, at the central server, the requested map data to the map data already present at the mobile client; and transmitting, from the central server to the mobile client, map data requested by the client, but excluding map data determined by the server to be already present in the client based on the previously transmitted summary information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A wireless client-server navigation system with reduced data transmission requirements, comprising:
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a central server accessing databases of geographical information; a mobile client operative to request and receive guidance from the central server, the mobile client including a memory for storing map data; a processor at the central server operative to compare a request for map data from the mobile client to a summary from the client regarding map data already stored at the mobile client so that the central server need only download the differences in the map data, if any, to the mobile client. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification