Wireless location finding is one of the key technologies for wireless sensor network.
GPS is the technology used but it can be used for the outdoor locations. When we deal
with the indoor location GPS does not work. Indoor locations include buildings like
supermarkets, big malls, parking spaces, universities, etc. In this area the accuracy of
the GPS location is greatly reduced. Location showed on the map in not correct when
the GPS is used under the indoor environments. But for the indoor localization it
requires the higher accuracy and the special purpose GPS is not feasible for the
current view. And also when GPS is used in the mobile device it consumes a lot of the
mobile battery to run the application which causes the drainage of the mobile battery
within some hours. So to find out the accurate location for indoor environment we use
the RSSI-based trilateral localization algorithm. The algorithm has the low cost and
the algorihm does not require any additional hardware support and moreover the
algorithm is easy to understand. The algorithm consumes very less battery as
compared the battery consumption of the GPS. Hence this algorithm has become the
mainstream localization algorithm in the wireless sensor network. With the
development of the wireless sensor network and the smart devices the WIFI access
points are also increasing. The mobile smart device detects three or more known
WIFI hotdpot position. And using the values from the WIFI routers it calculates the
current location of the mobile device. Under the indoor environment and can navigate
to the destination using the navigation function and also can enable the low
consumption of the smart mobile battery for the tracking purpose.