As the name suggests, Trilateration trilateration techniques uses three RTT values to estimate the coordinates of target node. In Trilateration trilateration technique, when several landmarks ping the specified Targettarget, three landmarks with smallest RTT values (probably nearest located landmarks) are selected and .The algorithm then algorithm tries to estimate the location on the basis of overlapping region of the drawn circles drawn around these selected landmarks. Figure .1 explains this in pictorial format1 depicts this technique. In Trilateration trilateration technique, the center of the overlapping region is considered as the location of the target node. Figure.1
https://confluence.slac.stanford.edu/download/attachments/90768644/tri.png 
There are many ways to implement trilateration technique such as
...
The performance of trilateration was quite has dramatically improved as shown in Figure 3.
