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

Algorithm 2

Initialization phase for blind nodes.

Input: The unique ID of current node ID_c

Define: HopInfo Packet HIP = {ID, position, hopInfo}

     NeighborInfo Packet NIP = {ID₁,⋯, ID_{n_init}}

     Anchor HopInfo List

          AHL = [ID_i, position_i, hopInfo_i]

     Neighbor Distance List NDL = [ID_i, d_i]

Procedure:

1: if received an HIP:

2: parse the HIP to obtain ID, position, hopInfo

3: ifID in AHL.ID and ID is an anchor:

4:  if hopInfo < AHL [ID].hopInfo

5:   AHL [ID].hopInfo = hopInfo

6: else ifID is an anchor:

7:  append [ID, position, hopInfo] to AHL

8:  send an HIP

9:  if hopInfo==1:

10:   record ID and RSSI

11: if received an NIP:

12: parse the NIP

13: ifID_c in NIP and sizeof (AHL) > 2:

14:  fori from 1 to sizeof (AHL):

15:   estimate d_i to each anchor based on hopInfo and the RSSI

16:  estimate the position of ID_c based on position in AHL and a series of d_i

17: change node type to pseudo-anchor