Interference Effects of Blue tooth on WLAN Performance

In this paper, Network stumbler version 0.4.0 was used to estimate the impact of impulsive interference on Wireless Local Area Network (WLAN) when Bluetooth coexist by measuring radiation from a WiFi Access Point (AP) in a homogeneous and heterogeneous scenarios. The parameters measured include Received Signal Strength (RSS) and Signal-to-Noise ratio (SNR) while Bit Error Rate (BER) performance was theoretically deduced from the measured data. Results obtained from the measurements of both scenarios were compared and used in describing the interference problem. The study revealed that Bluetooth impact on performance was minimally significant with mean degradation of 4.74% in RSS and 0.77% in SNR despite the fact that its signal are weak and are designed to accommodate WiFi devices by AFH technology.http://dx.doi.org/10.4314/njt.v34i1.2

Performance Analysis of Bluetooth Network in the Presence of WI-FI System

Many wireless technologies used to build local or personal area network (WLANs or WPANs) operate in the 2.4 GHz ISM band. Due to mutual interference, the coexistence of such devices working at the same time in the same area can be troublesome. This paper reports the result of Bluetooth performance  with 802.11b interference in term of BER of Bluetooth network. This study employed Agilent Advance Design system 2011 (ADS 2011) as methodology. The result revealed how Bluetooth network suffered degradation in terms of BER and the IEEE 802.11b interfering power and frequency offset. This study confirm previous finding. Further, the study recommends that the data rate of IEEE 802.11b should be taken into account in the performance evaluation of the Bluetooth network. Keywords: Bluetooth, Performance, and WI-FI syste

Evaluating interference in Bluetooth classic and Bluetooth low energy technology

Applied project submitted to the Department of Computer Science, Ashesi University College, in partial fulfillment of Bachelor of Science degree in Computer Science, April 2017Wireless communication is one of the dominant discoveries to mankind. Bluetooth, a wireless technology, is a crucial technology enabling wireless communications and more importantly, the internet of things. A recognized challenge in Bluetooth communication is the overlap of frequencies for specific time slots causing decreased throughput and delay of signals. This is described as Bluetooth interference. In order to improve communications in the internet of things, there is the need to evaluate and improve the Bluetooth technology. In this project, Bluetooth interference is evaluated using simulation. The two technologies involved are Bluetooth Classic and Bluetooth Low Energy. Simulation results are to help make informed decisions and recommendations in the usage of Bluetooth devices in coexistence. Findings in this study, confirm the presence of interference in the two technologies, and their relationship with the number of communicating pairs. Moreover, the incidence of interference is found to be relatively high in the Bluetooth Low Energy technology.Ashesi University Colleg

Coexistence and interference mitigation for WPANs and WLANs from traditional approaches to deep learning: a review

More and more devices, such as Bluetooth and IEEE 802.15.4 devices forming Wireless Personal Area Networks (WPANs) and IEEE 802.11 devices constituting Wireless Local Area Networks (WLANs), share the 2.4 GHz Industrial, Scientific and Medical (ISM) band in the realm of the Internet of Things (IoT) and Smart Cities. However, the coexistence of these devices could pose a real challenge—co-channel interference that would severely compromise network performances. Although the coexistence issues has been partially discussed elsewhere in some articles, there is no single review that fully summarises and compares recent research outcomes and challenges of IEEE 802.15.4 networks, Bluetooth and WLANs together. In this work, we revisit and provide a comprehensive review on the coexistence and interference mitigation for those three types of networks. We summarize the strengths and weaknesses of the current methodologies, analysis and simulation models in terms of numerous important metrics such as the packet reception ratio, latency, scalability and energy efficiency. We discover that although Bluetooth and IEEE 802.15.4 networks are both WPANs, they show quite different performances in the presence of WLANs. IEEE 802.15.4 networks are adversely impacted by WLANs, whereas WLANs are interfered by Bluetooth. When IEEE 802.15.4 networks and Bluetooth co-locate, they are unlikely to harm each other. Finally, we also discuss the future research trends and challenges especially Deep-Learning and Reinforcement-Learning-based approaches to detecting and mitigating the co-channel interference caused by WPANs and WLANs

Design of an Adaptive Frequency Hopping Algorithm Based On Probabilistic Channel Usage

Dealing with interference in the 2.4 GHz ISM band is of paramount importance due to an increase in the number of operating devices. For instance systems based on Bluetooth low energy technology are gaining lots of momentum due to their small size, reasonable cost and very low power consumptions. Thus the 2.4 GHz ISM band is becoming very hostile. Bluetooth specification enables the use of adaptive frequency hopping to improve performance in the presence of interference. This technique avoids the congested portions of the ISM band, however as the number of interferers increases for a given geographical environment, a greater number of bad channels are removed from the adapted hopping sequence. This results in longer channel occupancy, and consequently higher probability of collisions with coexisting devices, degrading their operation. At CoSa Research Group a novel algorithm, based on probabilistic channel usage of all channels (good and bad), is developed. The scheme is named Smooth Adaptive Frequency Hopping (SAFH) and uses an exponential smoothing filter to predict the conditions of the radio spectrum. Based on the predicted values, different usage probabilities are assigned to the channels, such as good channels are used more often than bad ones. The discrete probability distribution generated is then mapped to a set of frequencies, used for hopping. MATLAB/SIMULINK was used to investigate the performance of SAFH, in the presence of different types of interfering devices such as 802.11b , 802.15.4 and 802.15.1. Simulation study under different scenarios show, that our developed algorithm outperforms the conventional random frequency hopping as well as other adaptive hopping schemes. SAFH achieves lower average frame error rate and responds fast to changes in the channel conditions. Moreover it experiences smooth operation due to the exponential smoothing filter

Towards efficient coexistence of IEEE 802.15.4e TSCH and IEEE 802.11

A major challenge in wide deployment of smart wireless devices, using different technologies and sharing the same 2.4 GHz spectrum, is to achieve coexistence across multiple technologies. The IEEE~802.11 (WLAN) and the IEEE 802.15.4e TSCH (WSN) where designed with different goals in mind and both play important roles for respective applications. However, they cause mutual interference and degraded performance while operating in the same space. To improve this situation we propose an approach to enable a cooperative control which type of network is transmitting at given time, frequency and place. We recognize that TSCH based sensor network is expected to occupy only small share of time, and that the nodes are by design tightly synchronized. We develop mechanism enabling over-the-air synchronization of the Wi-Fi network to the TSCH based sensor network. Finally, we show that Wi-Fi network can avoid transmitting in the "collision periods". We provide full design and show prototype implementation based on the Commercial off-the-shelf (COTS) devices. Our solution does not require changes in any of the standards.Comment: 8 page

A Comparative Study of Wireless Protocols: Bluetooth, UWB, ZigBee, and Wi-Fi

(UWB, over IEEE 802.15.3), ZigBee (over IEEE 802.15.4), and Wi-Fi (over IEEE 802.11) are four protocol standards for short-range wireless communications with low power consumption. From an application point of view, Bluetooth is intended for a cordless mouse, keyboard, and hands-free headset, UWB is oriented to high-bandwidth multimedia links, ZigBee is designed for reliable wirelessly networked monitoring and control networks, while Wi-Fi is directed at computer-to-computer connections as an extension or substitution of cabled networks. In this paper, we provide a study of these popular wireless communication standards, evaluating their main features and behaviors in terms of various metrics, including the transmission time, data coding efficiency, complexity, and power consumption. It is believed that the comparison presented in this paper would benefit application engineers in selecting an appropriate protocol

Contributions to Improve Cognitive Strategies with Respect to Wireless Coexistence

Cognitive radio (CR) can identify temporarily available opportunities in a shared radio environment to improve spectral efficiency and coexistence behavior of radio systems. It operates as a secondary user (SU) and accommodates itself in detected opportunities with an intention to avoid harmful collisions with coexisting primary user (PU) systems. Such opportunistic operation of a CR system requires efficient situational awareness and reliable decision making for radio resource allocation. Situational awareness includes sensing the environment followed by a hypothesis testing for detection of available opportunities in the coexisting environment. This process is often known as spectral hole detection. Situational knowledge can be further enriched by forecasting the primary activities in the radio environment using predictive modeling based approaches. Improved knowledge about the coexisting environment essentially means better decision making for secondary resource allocation. This dissertation identifies limitations of existing predictive modeling and spectral hole detection based resource allocation strategies and suggest improvements. Firstly, accurate and efficient estimation of statistical parameters of the radio environment is identified as a fundamental challenge to realize predictive modeling based cognitive approaches. Lots of useful training data which are essential to learn the system parameters are not available either because of environmental effects such as noise, interference and fading or because of limited system resources particularly sensor bandwidth. While handling environmental effects to improve signal reception in radio systems has already gained much attention, this dissertation addresses the problem of data losses caused by limited sensor bandwidth as it is totally ignored so far and presents bandwidth independent parameter estimation methods. Where, bandwidth independent means achieving the same level of estimation accuracy for any sensor bandwidth. Secondly, this dissertation argues that the existing hole detection strategies are dumb because they provide very little information about the coexisting environment. Decision making for resource allocation based on this dumb hole detection approach cannot optimally exploit the opportunities available in the coexisting environment. As a solution, an intelligent hole detection scheme is proposed which suggests classifying the primary systems and using the documented knowledge of identified radio technologies to fully understand their coexistence behavior. Finally, this dissertation presents a neuro-fuzzy signal classifier (NFSC) that uses bandwidth, operating frequency, pulse shape, hopping behavior and time behavior of signals as distinct features in order to xii identify the PU signals in coexisting environments. This classifier provides the foundation for bandwidth independent parameter estimation and intelligent hole detection. MATLAB/Simulink based simulations are used to support the arguments throughout in this dissertation. A proof-of-concept demonstrator using microcontroller and hardware defined radio (HDR) based transceiver is also presented at the end.</p