Heuristic Localization Algorithm with a Novel Error Control Mechanism for Wireless Sensor Networks with Few Anchor Nodes

Algorithm 3

Error control phase for blind nodes.

Input: The unique ID of current node ID_c

   The node Type of current node Type_c

Define: Localization Request Packet LRP

  Location Packet LP = {ID, Position, Type}

  Reference List RL = [ID_i, p_i, d_i]

  Localization Confidence Score LCS

  Estimated Position EP

  Confidence List CL = [ID, EP, LCS, Type]

  Localization Decision LD

Procedures:

1: send an LRP

2: If received an LP:

3: parse the LP to obtain ID, position, Type

4: obtain the RSSI

5: if Type==reference:

6:  obtain distance estimation d via Eq. (1)

7:  append ID, position, d, to RL

8: If sizeof (RL) > =3:

9: calculate current geometric features via Eqs. (13) (14) and (15)

10: calculate the LCS of this localization by Eq. (19)

11: IfLCS > LCS in the last CL

12:  input the features to one-class SVM classifier to

       obtain a decision result LD

13:  IfLD==localization:

14:   estimate the location of current node ID_c by

       Eq. (10).

15:   change the type of current node to pseudo-anchor

16:   append [ID_c, EP, LCS, pseudo-anchor] to CL