scholarly journals Automatic Detection of Changes in Signal Strength Characteristics in a Wi-Fi Network for an Indoor Localisation System

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1828
Author(s):  
Marcin Luckner ◽  
Rafał Górak
Keyword(s):  
Quality Of Service ◽  
Dynamic System ◽  
Automatic Detection ◽  
Signal Strength ◽  
Access Point ◽  
Received Signal Strength ◽  
Strength Characteristics ◽  
The Mean ◽  
Indoor Localisation

This paper faces the issue of changing the received signal strength (RSS) from an observed access point (AP). Such a change can reduce the Quality of Service (QoS) of a Wi-Fi-based Indoor Localisation System. We have proposed a dynamic system based on an estimator of RSS using the readings from other APs. Using an optimal threshold, the algorithm recognises an AP that has changed its characteristics. Next, the system rebuilds the localisation model excluding the changed AP to keep QoS. For the tests, we simulated a change in the analysed Wi-Fi network by replacing the measured RSS by an RSS obtained from the same AP model that lies in another place inside the same multi-floor building. The algorithm was evaluated in simulations of an isolated single-floor building, a single-floor building and a multi-floor building. The mean increase of the localisation error obtained by the system varies from 0.25 to 0.61 m after the RSS changes, whereas the error increase without using the system is between 1.21 and 1.98 m. The system can be applied to any service based on a Wi-Fi network for various kinds of changes like a reconfiguration of the network, a local malfunction or ageing of the infrastructure.

scholarly journals Analysis of Received Signal Strength Quantization in Fingerprinting Localization

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3203 ◽  
Author(s):  
Syed Khandker ◽  
Joaquín Torres-Sospedra ◽  
Tapani Ristaniemi
Keyword(s):  
Quality Of Service ◽  
Indoor Localization ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Storage Space ◽  
Data Traffic ◽  
Positioning Accuracy ◽  
Hardware Configuration ◽  
Fine Resolution

In recent times, Received Signal Strength (RSS)-based Wi-Fi fingerprinting localization has become one of the most promising techniques for indoor localization. The primary aim of RSS is to check the quality of the signal to determine the coverage and the quality of service. Therefore, fine-resolution RSS is needed, which is generally expressed by 1-dBm granularity. However, we found that, for fingerprinting localization, fine-granular RSS is unnecessary. A coarse-granular RSS can yield the same positioning accuracy. In this paper, we propose quantization for only the effective portion of the signal strength for fingerprinting localization. We found that, if a quantized RSS fingerprint can carry the major characteristics of a radio environment, it is sufficient for localization. Five publicly open fingerprinting databases with four different quantization strategies were used to evaluate the study. The proposed method can help to simplify the hardware configuration, enhance security, and save approximately 40–60% storage space and data traffic.

scholarly journals A Generative Method for Indoor Localization Using Wi-Fi Fingerprinting

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2392
Author(s):  
Óscar Belmonte-Fernández ◽  
Emilio Sansano-Sansano ◽  
Antonio Caballer-Miedes ◽  
Raúl Montoliu ◽  
Rubén García-Vidal ◽  
...  
Keyword(s):  
Markov Model ◽  
Hidden Markov Model ◽  
Indoor Localization ◽  
Hidden Markov ◽  
Signal Strength ◽  
Access Point ◽  
Received Signal Strength ◽  
Machine Learning Algorithms ◽  
Forward Algorithm ◽  
Generative Method

Indoor localization is an enabling technology for pervasive and mobile computing applications. Although different technologies have been proposed for indoor localization, Wi-Fi fingerprinting is one of the most used techniques due to the pervasiveness of Wi-Fi technology. Most Wi-Fi fingerprinting localization methods presented in the literature are discriminative methods. We present a generative method for indoor localization based on Wi-Fi fingerprinting. The Received Signal Strength Indicator received from a Wireless Access Point is modeled by a hidden Markov model. Unlike other algorithms, the use of a hidden Markov model allows ours to take advantage of the temporal autocorrelation present in the Wi-Fi signal. The algorithm estimates the user’s location based on the hidden Markov model, which models the signal and the forward algorithm to determine the likelihood of a given time series of Received Signal Strength Indicators. The proposed method was compared with four other well-known Machine Learning algorithms through extensive experimentation with data collected in real scenarios. The proposed method obtained competitive results in most scenarios tested and was the best method in 17 of 60 experiments performed.

scholarly journals Automatic Detection of Missing Access Points in Indoor Positioning System †

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3595 ◽  
Author(s):  
Rafał Górak ◽  
Marcin Luckner
Keyword(s):  
Automatic Detection ◽  
Significant Loss ◽  
Classification Error ◽  
Positioning System ◽  
Random Forest Algorithm ◽  
Access Points ◽  
The Mean ◽  
Academic Building ◽  
Indoor Positioning System ◽  
Indoor Localisation

The paper presents a Wi-Fi-based indoor localisation system. It consists of two main parts, the localisation model and an Access Points (APs) detection module. The system uses a received signal strength (RSS) gathered by multiple mobile terminals to detect which AP should be included in the localisation model and whether the model needs to be updated (rebuilt). The rebuilding of the localisation model prevents the localisation system from a significant loss of accuracy. The proposed automatic detection of missing APs has a universal character and it can be applied to any Wi-Fi localisation model which was created using the fingerprinting method. The paper considers the localisation model based on the Random Forest algorithm. The system was tested on data collected inside a multi-floor academic building. The proposed implementation reduced the mean horizontal error by 5.5 m and the classification error for the floor’s prediction by 0.26 in case of a serious malfunction of a Wi-Fi infrastructure. Several simulations were performed, taking into account different occupancy scenarios as well as different numbers of missing APs. The simulations proved that the system correctly detects missing and present APs in the Wi-Fi infrastructure.

scholarly journals Análisis basado en parámetros QoS para el servicio VoIP sobre wireless en un campus universitario [Analysis based on QoS parameters for VoIP service on a wireless network within a university campus]

2014 ◽  
Author(s):  
Alexander Olave ◽  
Luis Felipe Valencia ◽  
Juan Carlos Cuéllar
Keyword(s):  
Quality Of Service ◽  
Wireless Network ◽  
Packet Loss ◽  
Cost Benefit ◽  
Access Point ◽  
University Campus ◽  
Delay Jitter ◽  
Qos Parameters ◽  
La Red

Resumen Voz sobre IP, VoIP, es uno de los servicios con mayor desarrollo bajo plataformas inalámbricas; actualmente se ha iniciado su implementación como alternativa frente a la PSTN (red pública conmutada). El interés por VoIP radica en su relación costo-beneficio, ya que las organizaciones pueden utilizar la misma plataforma de su red de datos para transmitir voz. Por lo anterior, es importante que la organización tenga claro que, para garantizar el buen funcionamiento del servicio de VoIP, es decir para ofrecer QoS, se debe realizar la medición de parámetros que afectan la calidad del servicio como lo son: el retardo, la variación del retardo, el ancho de banda y la pérdida de paquetes. Este artículo analiza y valida los parámetros de QoS necesarios para garantizar el buen funcionamiento del servicio de VoIP sobre la red inalámbrica del campus de la Universidad Icesi. Se realizan pruebas en diferentes escenarios para mostrar que no solo factores como el retardo, y su variación, influyen en la calidad de servicio, sino que también la intensidad de la señal que recibe el cliente desde los puntos de acceso.Palabras Clave: Voz sobre IP, Calidad de servicio, Pérdida de paquetes, Retardo, Variación del Retardo, Intensidad de Señal. Abstract VoIP is one of the services that has been developing over under this type of wireless platforms and today has begun to implement as an alternative to the PSTN (Public Switched Telephone Network). The interest in VoIP is its cost-benefit ratio, and that organizations can use the same platform for their data network to transmit voice. Therefore it is important that the organization is clear that to ensure the smooth operation of the VoIP service, ie provide QoS, you must perform the measurement of parameters that affect the quality of service such as: delay, jitter, bandwidth, packet loss. In this paper we analyze and validate the QoS parameters needed to ensure the smooth operation of VoIP over wireless network on the Icesi University campus. We performed a series of tests in different scenarios to show that not only factors such as delay and jitter influencing the quality of service, but also the client signal strength received from of the AP (Access Point).Keywords: Voice over IP, Quality of service, Packet Loss, Delay, Delay variation, signal intensity.

scholarly journals Quality of Care Delivered to Tuberculosis Patients among Public Hospitals in Central Northeast Ethiopia

2020 ◽  
Vol 30 (5) ◽  
Author(s):  
Balkew Asegidew Tegegn ◽  
Betregiorgis Zegeye Hailu ◽  
Birhanu Damtew Tsegaye ◽  
Gashaw Garedew Woldeamanuel ◽  
Wassie Negash
Keyword(s):  
Quality Of Service ◽  
Quality Of Care ◽  
Quality Of Healthcare ◽  
Cross Sectional Study ◽  
Public Hospitals ◽  
Binary Logistic Regression Analysis ◽  
Cross Sectional ◽  
The Mean ◽  
Process Dimension

BACKGROUND: Inappropriate Tuberculosis (TB) diagnosis and treatment contributes to unfavorable health outcome among TB patients. Improving quality of healthcare service helps to avert TB related morbidity. Despite these facts, the level of quality of service is not known in the hospitals. Hence, the present study was conducted to assess the quality of care delivered to TB patients among publichospitals.METHODS: A facility-based cross-sectional study was conducted from March 15 to April 30, 2019 in North Shewa Zone, Amhara region, Ethiopia. All TB patients who had follow-up in the hospitals were included. This resulted in the involvement of 82 TB patients. Data was collected by trained data collectors using facility audit, clinical observation checklists, structured questionnaire and in-depth interview. Data was analyzed using SPSS version 20. Binary logistic regression analysis was done to identify the predictors of patients’ satisfaction.RESULTS: In this study, 82 respondents with a mean age of 36.48 (±13.27) years were participated. The mean quality score for structural dimension was 59.5%, and 53.7% of participants were found to be satisfied in outcome dimension. The mean score for process dimension of quality of service were 67.9%. Having TB symptoms were significantly associated with the level of patientsatisfaction towards TB care [AOR = 0.217, p = 0.015].CONCLUSION:Quality of TB services from structural and outcome dimension were low and higher in process dimension. Thus, careful attention on the quality of services will help to reduce the burden of TB.

scholarly journals PERFORMANCE ANALYSIS AND QOS FRAMEWORK OF FLY WİRELESS NETWORK

2019 ◽  
Vol 01 (02) ◽  
pp. 103-115
Author(s):  
Durai Pandian M
Keyword(s):  
Quality Of Service ◽  
Performance Analysis ◽  
Wireless Network ◽  
Wireless Mesh Network ◽  
Environmental Changes ◽  
Mesh Networks ◽  
Access Point ◽  
Mesh Network ◽  
Wireless Mesh

The spread out of wireless mesh network has made possible the extended range of communication network that are impractical due to environmental changes in a wired access point, these wireless mesh network does not require much competence to set it up as it can be set very fast at a cheap rate, and the conveyancing of messages in it happens by selecting the shortest path, these wireless mesh built-in with irrepressible and invulnerable identities come with an endurance to temporary congestion and individual node failure. This results in an architecture providing a better coverage, flaw indulgent with higher bandwidth compared to other wireless distributed systems. But faces the limitation on power conservation. The battery activated mesh nodes loses their resources on perception, processing and transmission of the data’s, though these batteries or accumulators comes with energy regaining capability still draw backs show up as their nature of energy regaining are unexposed. So the performance analysis of fly wireless network which proposes a uninterrupted wireless mesh networks aims at providing a best measure of performance that is the best quality of service on the meshwork by providing an improved energy gleaning using potency segregation (IGPS) which empowers each node to have self- contained accumulation of energy achieving heightened adaption with energy consumption kept at a minimum. The gross functioning of the proposed is examined on the bases of delay and packet loss to prove the quality of service acquired.

scholarly journals A Novel Enhanced Positioning Trilateration Algorithm Implemented for Medical Implant In-Body Localization

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Peter Brida ◽  
Juraj Machaj
Keyword(s):  
Signal Strength ◽  
Received Signal Strength ◽  
Position Estimation ◽  
Time Of Arrival ◽  
Medical Implant ◽  
Exact Position ◽  
Two Phases ◽  
Positioning Algorithm ◽  
Selection Of

Medical implants based on wireless communication will play crucial role in healthcare systems. Some applications need to know the exact position of each implant. RF positioning seems to be an effective approach for implant localization. The two most common positioning data typically used for RF positioning are received signal strength and time of flight of a radio signal between transmitter and receivers (medical implant and network of reference devices with known position). This leads to positioning methods: received signal strength (RSS) and time of arrival (ToA). Both methods are based on trilateration. Used positioning data are very important, but the positioning algorithm which estimates the implant position is important as well. In this paper, the proposal of novel algorithm for trilateration is presented. The proposed algorithm improves the quality of basic trilateration algorithms with the same quality of measured positioning data. It is called Enhanced Positioning Trilateration Algorithm (EPTA). The proposed algorithm can be divided into two phases. The first phase is focused on the selection of the most suitable sensors for position estimation. The goal of the second one lies in the positioning accuracy improving by adaptive algorithm. Finally, we provide performance analysis of the proposed algorithm by computer simulations.

scholarly journals Research and Application of Underground WLAN Adaptive Radio Fingerprint Database

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1182
Author(s):  
Jiansheng Qian ◽  
Mingzhi Song
Keyword(s):  
Signal Strength ◽  
Access Point ◽  
Received Signal Strength ◽  
Reference Points ◽  
Normal Operation ◽  
Positioning System ◽  
Widespread Application ◽  
Radio Fingerprint ◽  
Fingerprint Database ◽  
User Location

Fingerprint positioning based on WiFi in coal mines has received much attention because of the widespread application of WiFi. Fingerprinting techniques have developed rapidly due to the efforts of many researchers. However, the off-line construction of the radio fingerprint database is a tedious and time-consuming process. When the underground environments change, it may be necessary to update the signal received signal strength indication (RSSI) of all reference points, which will affect the normal working of a personnel positioning system. To solve this problem, an adaptive construction and update method based on a quantum-behaved particle swarm optimization–user-location trajectory feedback (QPSO–ULTF) for a radio fingerprint database is proposed. The principle of ULTF is that the mobile terminal records and uploads the related dataset in the process of user’s walking, and it forms the user-location track with RSSI through the analysis and processing of the positioning system server. QPSO algorithm is used for the optimal radio fingerprint match between the RSSI of the access point (AP) contained in the dataset of user-location track and the calibration samples to achieve the adaptive generation and update of the radio fingerprint samples. The experimental results show that the radio fingerprint database generated by the QPSO–ULTF is similar to the traditional radio fingerprint database in the statistical distribution characteristics of the signal received signal strength (RSS) at each reference point. Therefore, the adaptive radio fingerprint database can replace the traditional radio fingerprint database. The comparable results of well-known traditional positioning methods demonstrate that the radio fingerprint database generated or updated by the QPSO–ULTF has a good positioning effect, which can ensure the normal operation of a personnel positioning system.

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