Simultaneous GPS or S-GPS is a method to allow a
GPS
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
reception and
CDMA
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communicatio ...
communications to operate simultaneously in a mobile phone.
Ordinarily,
cellular geolocation and a built-in GPS receiver is used to determine the location of an
E911
Enhanced 911, E-911 or E911 is a system used in North America to automatically provide the caller's location to 911 dispatchers. 911 is the universal emergency telephone number in the region. In the European Union, a similar system exists known as ...
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
radio receiver.
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
A location-based service (LBS) is a general term denoting software services which use geographic data and information to provide services or information to users. LBS can be used in a variety of contexts, such as health, indoor object search, ent ...
. The use of two radios with a single antenna imparts new design challenges, such as leakage of the voice transmitter signal into the GPS receiver circuitry. The commercial availability of S-GPS chipsets from manufacturers such as
Qualcomm, has led to adoption of the method in newer handsets.
See also
*
Assisted GPS
Assisted GNSS (A-GNSS) is a GNSS augmentation system that often significantly improves the startup performance—i.e., time-to-first-fix (TTFF)—of a global navigation satellite system (GNSS). A-GNSS works by providing the necessary data to the ...
References
Mobile technology
Global Positioning System
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