Table 2: Comparison of localization schemes.

Method #BN #AntennaSYNTimeAELE

ALRD22/BNN<1 s6°–8°89 cm
RIMA13/BNY1.6 s
EDoA1/SNN200 s4°–8°
RAL22/BNN180 s4°–8°76 cm

#BN: the number of beacon nodes.
#Antenna: the number of antennas per beacon node (BN) or per sensor node (SN).
AE: angle error.
LE: localization error.
SYN: time synchronization requirement.