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 frequency

Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

 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

Qualcomm

Qualcomm is an American global telecommunication corporation that designs, manufactures and markets digital wireless telecommunications products and services based on its code division multiple access technology and other technologies. Headquartered in San Diego, CA, USA...

, has led to adoption of the method in newer handsets.