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Method for guiding navigation using low-power, fixed, wireless transceivers in a handheld device

IP.com Disclosure Number: IPCOM000020406D
Publication Date: 2003-Nov-20
Document File: 5 page(s) / 158K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for guiding navigation using low-power, fixed, wireless transceivers in a handheld device. Benefits include improved functionality and improved performance.

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Method for guiding navigation using low-power, fixed, wireless transceivers in a handheld device

Disclosed is a method for guiding navigation using low-power, fixed, wireless transceivers in a handheld device. Benefits include improved functionality and improved performance.

Background

         Conventional methods of location determination using wireless network nodes are limited due to having fixed antennas and little if any built-in computation capability in the nodes themselves. Alternatively, specific interactions related to location determination are built in the devices with which they cooperate. Location is estimated by combining a physical map comparison and estimating signal strength to the device as an indication of proximity. Due to intervening objects, RF reflections, and the large-granularity used to measure signal strength, these methods are subject to a high amount of error. When they can determine location with some accuracy, they cannot determine the direction of travel or velocity, except by possibly very crude estimates.

         Some marine or aircraft navigation systems use rotating beacons or split-frequency beacons for direction indication from known locations.

         Surveyors use least-squares techniques to combine direction measurements containing errors when they have enough measurements for an over-determined position solution to obtain a refined solution.

General description

         The disclosed method determines location, direction of travel, and velocity using a small hand-held transceiving device in conjunction with a network of fixed, wireless transceivers (hotspots). The method utilizes specialized transmission and reception techniques. Information is coordinated among the network access points and with the handheld component. As a result, the current location, speed, and direction of the handheld device can be determined with reasonable accuracy. For example, the device can guide the user to a predetermined location within the range of the wireless network. Alternatively, the device can deliver targeted content based on the known physical context of the user’s current location.

         The disclosed method has several components:

•         Handheld device that contains a very low-power radio transceiver

•         Minimum of two fixed-position powered transceivers with range and spacing similar to conventional wireless networks

•         Specialized antenna system in each of the above fixed-position transceivers that enables a narrow beam, rotating signal to be transmitted at a known interval or rotation rate

•         Transceivers with a CPU with sufficient power to process a simple communication protocol and make special-purpose mathematical computations

•         Database, either distributed among the network nodes or in a single, network accessible location, which contains a mapping of the node IDs and their physical location

         The transceiver could be an RF-powered device, which requires no self-contained power supply. The handheld device requires a rudimentary display of...