This paper opens with an introduction to the term localization techniques using RSS. The study contains concepts, requirements and specifications for each category of techniques. The paper also presents pros and cons for investigated localization techniques and conducts comparisons between them.

This paper presents the advantages of using a wideband spectrum adopting multi-carrier to improve targets localization within a simulated indoor environment using the Time of Arrival (TOA) technique. The study investigates the effect of using various spectrum bandwidths and a different number of carriers on localization accuracy. Also, the paper considers the influence of the transmitters’ positions in line-of-sight (LOS) and non-LOS (NLOS) propagation scenarios. It was found that the accuracy of the proposed method depends on the number of sub-carriers, the allocated bandwidth (BW), and the number of access points (AP). In the case of using large BW with a large number of subcarriers, the algorithm was effective to reduce localization errors compared to the conventional TOA technique. The performance degrades and becomes similar to the conventional TOA technique while using a small BW and a low number of subcarriers.

This paper introduces a review article on indoor localization techniques and technologies. The paper starts with current localization systems and summarizes comparisons between these systems in terms of accuracy, cost, advantages, and disadvantages. Also, the paper presents different detection techniques and compare them in terms of accuracy and cost. Finally, localization methods and algorithms, including angle of arrival (AOA), time of arrival (TOA), and recived signal strength (RSS) are introduced. The study contains concepts, requirements, and specifications for each category of methods presents pros and cons for investigated methods, and conducts comparisons between them.

This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and supported by Line of Sight (LoS) and Non-LoS measurements data. The study also investigates other factors that may affect the WI sensitivity, including antenna dimensions, antenna pattern, and accuracy of the environment design. In the experiment, single and double reflections from concrete walls and wooden doors are analysed. Experimental results were compared to those obtained from simulation using the WI. It was found that materials selected from the literature should be similar to those of the environment under study in order to have accurate results. WI was found to have an acceptable performance provided certain conditions are met.

For the aim of surface refractivity analysis, the overall territory of Quebec has been divided in a desired number of areas from North to South using clustering analysis. The meteorological data used in the analysis are collected from 50 stations located in various climatic regions over Quebec for the year 2013. It is found that the best input data for the identification of areas is the water vapour pressure. The results show that the surface refractivity increase from North to South and the maximum values for all areas are observed in July or in August. However, the variation of the surface refractivity remains in a relatively small interval in comparison to the variation observed in some tropical countries, particularly Nigeria.

This paper introduces a study on verifying received power at WLAN frequencies in indoor environments, Wireless InSite is a popular electromagnetic ray-tracing software which is widely used for predicting
channel behaviour in indoor and outdoor environments. The study compares software-generated data with measurements collected through 3rd floor Chesham Building, University of Bradford, at WLAN frequencies, the paper also investigates the effect of changing settings on results accuracy and computational time, and finally, the paper presents a comparison between simulation results with empirical models.

Thirty‐nine years of archived meteorological data measured at two stations located in the
northern and southern parts of Quebec, Canada are used to estimate the surface refractivity and its dry
and wet components. The results of the comparison of the obtained estimates showed that for all months the values of the dry component are higher in the northern part, whereas the values of the wet component are higher in the southern part. Due to this, for several months of the year, the values of the surface refractivity are higher in the northern part and for the remaining months in the southern part. Moreover, in both parts, August is the month where the highest values of the surface refractivity were recorded. In this particular month, the slope of the surface refractivity trend in the northern part is several times higher than that in the southern part. The obtained results show that the performance of the used direct smoothing forecasting technique depends on the deviation between the values of N in the current year and the previous year.

A survey of indoor propagation characteristics is presented, including different models for path loss,
shadowing and fast fading mechanisms, different channel parameters including signal strength, power
delay, coherence bandwidth, Doppler spread and angle of arrival. The concepts of MIMO channels
are also covered. The study also explores many types of deterministic channel modelling, such as
Finite Difference Time Domain, Finite Integration Method, Ray tracing and the Dominant path model.
Electromagnetic properties of building materials, including frequency dependence, are also investigated
and several models for propagation through buildings are reviewed.

In this paper, a comparative study between different indoor path loss prediction models is conducted.
The investigated models include averaged wall loss model (AWM), single slope model (SSM), linear
attenuation model (LM), two slope model (TSM), partitioned model (PM), and Motley-Keenan model
(MKM). The models were tested in a simulated environment of the 3rd floor of Chesham building, the
University of Bradford, a different set of frequencies were used including 28 GHz, 60 GHz, and 73.5 GHz,
TSM shows the best performance, both AWM and MKM tend to have a similar performance at millimetrefrequencies, both models’ prediction for corridor and LOS regions are pessimistic while TSM, SSM, and LM have better estimations in these regions.

Alternative healthcare solutions have been identified as a viable approach to ameliorate the
increasing demand for telehealth and prompt healthcare delivery. Moreover, indoor ocalization using
dierent technologies and approaches have greatly contributed to alternative healthcare solutions.
In this paper, a cost-eective, radio frequency identification (RFID)-based indoor location system that
employs received signal strength (RSS) information of passive RFID tags is presented. The proposed
system uses RFID tags placed at dierent positions on the target body. The mapping of the analysed
data against a set of reference position datasets is used to accurately track the vertical and horizontal
positioning of a patient within a confined space in real-time. The Euclidean distance model achieves
an accuracy of 98% for all sampled activities. However, the accuracy of the activity recognition
algorithm performs below the threshold performance for walking and standing, which is due to
similarities in the target height, weight and body density for both activities. The obtained results
from the proposed system indicate significant potentials to provide reliable health measurement tool
for patients at risk.