Question

Wireless Sensor Networks/Internet of Things Topic

What are the main issues that affect localization?

Answer 1

Brief answer :

(WSNs) has wide range of applications but there are several applications(critial for daily life uses) where the sensor data is not useful without the coordinates and can result in an incorrect interpretation of the given data .

For example there is a radiation detection project using thousands of sensors across country. and one sensor detects radiations in the zone but if coordinate information is incorrect/not know situation would be catestropic, particularly if the coordinate's information is not known.

Therefore, localization is of Paramount importance in operations of WSNs.

Below are the detailed issues and challenges being hindered in localization of the sensor nodes in WSNs.

Detailed answer

A Wireless Sensor Network (WSN) is a network of independent, low-cost and tiny sensing stations also known as sensor nodes which may or may not have their own computing capacities at its own to analyze the sensor readings/results.

sensor nodes are used to monitor the surrounding environment for some activity and send the sensory data to central unit.

Localization schemes in WSNs used to determine the coordinate’s information of the reporting sensor nodes and these coordinates information can be locally or globally significant based on the use case.

ISSUES AND CHALLENGES IN LOCALIZATIONN OF WSNS:

1. Efficient Energy Consumption in WSNs Localization

higher energy consumption requires frequent recharege/battry change for sensors which is very costly.

2. Localization in 3D WSNs :

sensor nodes in a two dimensional (2D) plane can determine location easily but in 3D such as flight path monitoring sensors are not accurate till now, also there are nano tech sensors being used in healthcare- accurate location inside the body is headache to scientist till now.

3.Localization in Mobile Wireless Sensor Networks (MWSNs)

  maintaining the connectivity and maximizing the lifetime of the network are of critical

on Moving target position is still inaccurate

4.Secure Localization

as per recent incidents of terrorism -WSNs may be deployed in hostile environments and the localization procedure is vulnerable to many localization-specific attacks

5. Beacon Movement Problem in WSNs Localization

if a beacon is moved unexpectedly to a location other than its supposed location, then sensor would have to know here its beacon is , major challage today .

6.Localization in un-trusted environment

7.Minimum Number of Beacons: today also we need at least equal beacons as of number of sensors out there on field , minimizing number of beacons causes signal/connectivity /data loss with the sensors.

8.Error in Interferometric Ranging Based Localization

if there are sensors connecting to each other via a series placed from each other at some distance, as shown below

groudStation1------S1-------------S2------------------------S3---------------------S4-----------------------groundStating2.

while sending data from GS1 to GS2 if there is an error in readings , propagating errors subsequently creates a very large deviation in accuracy and GS2 receiving results are totally invalid sometimes.