Qualcomm seeks patent for mobile altitude measuring device

New Delhi, Oct 3 : Qualcomm Inc, a US-based pioneer of CDMA based mobile telephony, has filed a patent application in the country for its recent invention of a device, which could be used to determine altitude of a mobile phone in any environment, more accurately than GPS.

Qualcomm, leading developer and innovator of the mobile devices and chips, has approached the Controller General of Patents, Designs and Trade Marks by filing patent application.

Admitting the application, the authorities have published the claims made by the company in their latest patent journal (PJ) giving a public notice.

The company has already presence in India and its other technologies are being used by leading domestic CDMA players such as Anil Ambani group firm RCom, Tata Indicom and Shyam Telelinks.

In its patent application filed on June 30 this year, it has claimed that the present invention can trace the altitude of mobile phone in any environment by using information from dead reckoning sensors, such as accelerometers, gyroscopes and geomagnetic sensors.

"The method and apparatus herein consist of combining the pressure information with information from dead reckoning sensors, such as accelerometers, gyroscopes and geomagnetic sensors and information from temperature sensors to separate what constitutes a change in altitude from a change in environmental pressure or temperature," the company claimed.

Geneva-based UN agency World Intellectual Property Organisation (WIPO) has already granted patent for this invention, which is developed by Thomas G Wolf of Qualcomm.

Position determination is an important and growing feature of cellular telephones and other handheld mobile devices. The ability to determine the location of a cellular telephone is desirable for emergency calls and for a variety of commercial purposes, generally called Location Based Services.


The most prevalent approach to determine location is to embed Global Positioning System (GPS) navigation receiver capability into the mobile device. However, GPS-based positioning has limitations. GPS systems cannot resolve altitude accurately, it said.

Comparing its invention with GPS technique, the company explains that the GPS-based position determination is based upon determining the distance that the signal travels from the GPS satellites.

So, it is not very accurate in indoor environments and other locations, where satellite signals can be blocked, distorted or reflected. In addition, because the satellites are usually high in the sky, the GPS-based position is less accurate in altitude, than in the horizontal position.

However, the present method and apparatus of US chipmaker minimises the effects of changes in environmental and temperature pressure on the determination of altitude, it claimed.

"An object of the present invention is to accurately determine the altitude of a mobile device taking into consideration environmental changes," the company said.