This article needs attention from an expert in Technology. Please add a reason or a talk parameter to this template to explain the issue with the article. WikiProject Technology (or its Portal) may be able to help recruit an expert.(August 2009)
Simultaneous GPS or S-GPS is a method to enhance a mobile phone's satellite-based position reporting ability to a carrier.
Ordinarily, a built-in GPS device is used to determine the location of an E911 call made from CDMA phones. By using a time-multiplexed scheme called TM-GPS, the reception of the telephone call and the GPS signal are alternated one after the other, requiring only one RF radio.
As the name implies, Simultaneous GPS allows a cellphone to receive both GPS and voice data at the same time, which improves sensitivity and allows service providers to offer location-based services. The use of two radios with a single antenna imparts new design challenges, but the commercial availability of S-GPS chipsets, from manufacturers such as Qualcomm, has led to adoption of the method in newer handsets and Samsung's latest processors (as the ones used in Galaxy S III, Note 10.1, Note 2).