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The provision of reliable location estimates in case of unpredicted failures or malicious attacks, which inject faults and compromise the performance of the positioning system, is very important. Thus, our main interest is on the fault tolerance of WLAN fingerprint-based methods, rather than the absolute positioning error in the fault-free case. We study the Nearest Neighbor method and as a first...
This paper presents an indoor positioning technique based on neural networks (NN). The received signal strengths (RSS) sensed by Zigbee wireless sensor network were used to estimate the position of object. From the simulation results shown, the NN technique proposed still has the high accuracy even the signal strengths sensed are unstable. Besides, from the experimental results shown, it is concluded...
In this paper, we introduce Radio-On-Demand (ROD) wireless LAN (WLAN) in which access points (APs) are put into a sleep mode during idle periods and woken up by stations (STAs) upon communications demands. The on-demand wake-up is realized by a wake-up receiver which is equipped with each AP and is used to detect a wake-up signal transmitted by STA. In this paper, in order to reduce the hardware installation...
In this paper, we establish a channel ranking strategy for wireless sensor networks (WSN) in the presence of WLAN interference. The packet delivery ratio (PDR) of a sensor link is the performance metric used for channel ranking. The PDR is defined as a function of the signal-to-interference-and-noise-ratio (SINR) at the sensor and the time domain transmission characteristics of the interferer that...
The characteristic of the IEEE802.11 protocol and the principle of the DoS attack against 802.11 WLAN is analyzed in this paper. a general system model for WLAN network intrusion detection and 802.11 DoS attack analysis based on the intelligent terminal is advanced. On the base of the research on using NDIS IMD to realize packet capturing and its developing process, a system of intrusion detection...
In this paper, performance of a wireless communication system based on wideband signals has been experimentally evaluated in a point-to-point topology for potential deployment in industrial environments. A class of wideband signals based on Chirp Spread Spectrum (CSS) modulation has been chosen in this work. Two experimental scenarios have been considered: 1) coexistence with other wireless systems,...
In order to develop and validate network protocols and architectures, proper tools are required to validate the design and to analyze the various aspects of the architecture or its components. This is typically addressed by measurements using real hardware, via simulations or emulations or by using a combination thereof. In this paper we present our development framework to implement and validate...
This paper proposes a scheme to solve issue of unfair throughput by the capture effect. Wireless LAN (WLAN) systems suffer from the hidden terminal problem, which is occurred by the unreached signal for non-neighbor radio terminals. Since the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) for WLANs does not adequately solve this problem, transmitted packets collide more frequently...
We explore the use of IEEE 802.11 wireless technology to support health monitoring application, by providing ubiquitous connectivity while allowing patients greater mobility. The acquisition of electrocardiogram (ECG) is used as an example to highlight the engineering choices, such as packetization and access control rules, that must be made in designing a wireless transport. The error-prone nature...
The following topics are dealt with: wireless communications and networking WCN/WLAN/WiMAX; optical communications and networking OCN; mobile communications/wireless/mobility; mobile ad-hoc and sensor mesh networks; network management and services; UWD/RFID/OFDM and Nano/Bio, and; quality of service, traffic management and dynamic spectrum access networks.
This paper presents an empirical study of the effects of the channel occupation on the consumption of actual IEEE 802.15.4/ZigBee motes. The study is focused on the current demanded by a sensor node in a simple beaconless star topology when the CSMA contention algorithm introduces idle times in the activity of the radio transceiver. For this purpose, the developed testbed permits to define the probability...
Today, positioning techniques like GPS already has satisfied performance in outdoor environment, but there are many problems in indoor positioning, and some conventional methods for indoor positioning also have their disadvantage. In order to overcome these problems and find a better performance over these methods, we proposed a new positioning and tracking method. It is based on the wireless sensor...
The application of WSN/ZigBee is growing popularity and how to connect WSN/ZigBee to the present standard network seamlessly is an issue what is worth studying. In this paper, it designs and realizes a ZigBee—Wi-Fi wireless gateway based on STM32W108 RF chip and embedded Wi-Fi module. In ZigBee network, wireless gateway as a sink, it receives data from sensor nodes and interacts with them. In WLAN,...
To keep healthcare costs under control, a high-level of medication adherence, or compliance with medication regimen, must be achieved. In this paper, we show how wireless technologies can be used to improve medication adherence. More specifically, we present the design, operation, and evaluation of a wireless medication system, termed Smart Medication Management System (SMMS). We also present multiple...
Being reliable and real-time, are the two most challenging requirements of wireless sensor and actuator networks (WSAN) due to the shared, error-prone and nondeterministic behaviour of wireless communication medium. In this paper, an adaptive data-rate and space-time coding (STC) scheme has been proposed for the IEEE 802.11-based Soft-Real-Time WSAN's utilizing Enhanced Distributed Channel Access...
Interference is a crucial factor that impacts the overall throughput performance of IEEE 802.11-based wireless networks. As such, understanding interference characteristics is essential towards the optimal management and operation of these networks. In this paper, we use a conducted testbed (that allows us to completely control the signal propagation and received signal strength) to systematically...
In this paper, we perform a detailed study of the Binary Exponential Back-off Algorithm (BEBA) that is widely used in distributed MAC protocols to avoid collision when more than one machine try to access the medium in ad hoc network at the same time. We begin with a generalized framework of modeling of BEBA. Then we identify a key difference between BEBA and the commonly assumed p-persistent model...
Current 802.11 networks do not typically achieve the maximum potential throughput despite link adaptation and cross-layer optimization techniques designed to alleviate many causes of packet loss. A primary contributing factor is the difficulty in distinguishing between various causes of packet loss, including collisions caused by high network use, co-channel interference from neighboring networks,...
Transmission Control Protocol (TCP) was considered unsuitable for Low power and Lossy Networks (LLNs) due to the characteristics LLN devices (low computing power, strong energy constraint, etc.) and to the absence of IP layer on the network layer. Recently, the IPv6 over Low power Wireless Personal Area Networks (6LoWPANs) has been introduced as an adaptation layer for IPv6 over LLNs. Thanks to the...
Over the last decade cooperative communication in wireless sensor networks (WSN) received much attention. A lot of works have been done to propose a MAC layer that supports cooperative relaying. The majority of these works tried to adapt the IEEE 802.11 MAC protocol to sensor networks. The adapted protocols use a lot of overhead (such as the use of RTS/CTS as well as other messages used to allow cooperation)...
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