Accurate Localization Algorithm in Wireless Sensor Networks in the Presence of Cross Technology Interference

Usman Nazir, Ijaz Haider Naqvi and Murtaza Taj

Lahore University of Management Sciences (LUMS), Pakistan

Additional information: http://adcom.lums.edu.pk/http://cvlab.lums.edu.pk/

3. Approaches 4. Proposed Localization Algorithm

1. Motivation

Challenges

5. Channel Selection Procedure

• Cross Technology Interference

2. Problem Statement

6. Experimental Results

Indoor Localization

Home Automation Healthcare Smart Energy Navigation

Current Practice: Wi-Fi

Inaccurate Meters of error

Fragile Easily affected by dynamics

Future Promise: ZigBee

Accurate

Low cost

Low power

Programming over-the-air via PORTAL

Mesh Networking Standard

• Accurate Localization

Centralized and Distributed Algorithms

Range free and Range based Algorithms

Anchor free and Anchor based Algorithms

Communication cost Distributed computation

RSSI, AoA, TDoA

Global coordinates

Need extra hardware for AoA and TDoA

Not much accurate

Neighboring and Hop Couting

Expensive GPS receivers

Relative coordinates

Cost effective

Distributed, Range and Anchor based Localization Algorithm

Localization using Trilateration

Experimental Setup

InterferenceInterference

Broadcast of Beacon signals

ZigBee Channel Selection

Range Estimation

Location Estimation using Multilateration

Kalman Filter Based Error Minimization

Distance (meter)

Dis

tan

ce (

met

er)

Energy Scan on ZigBee Channels

Channel Selection with Average RSSI

Data Transmission on Selected Channel

Packet Error Ratio < Threshold

Yes

No

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11

Dis

tan

ce (

met

ers)

Distance (meters)

Original Position and Estimated Position of Mobile Node

Original Position

Estimated Position using Trilateration

Estimated Position using Trilateration+Averaging Function

Estimated Position using Proposed Algorithm

RMSE=1.6 m (Trilateration)RMSE=0.15 m (Proposed Algorithm)

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

1 2 3 4 5 6

RSS

I (d

Bm

)

Time (seconds)

RSSI Variations on ZigBee Channels

Channel 11 Channel 12 Channel 13 Channel 14

Channel 15 Channel 16 Channel 17 Channel 18

Channel 19 Channel 20 Channel 21 Channel 22

Channel 23 Channel 24 Channel 25 Channel 26