WSNs	Wireless sensor networks
SVM	Support vector machine
LPCC	Linear predictive coding coefficient
HMM	Hidden Markov model
PCA	Principal component analysis
LOS	Line-of-sight
NLOS	Non-line-of-sight
RSSI	Received signal strength indicator
EMD	Empirical mode decomposition
IMFs	Intrinsic mode functions
ApEn	Approximate entropy
SD	Standard deviation