Coexistence Mechanism for Industrial Automation Network

Increase in the number of coexisting networks in Industrial, Scientific and Medical (ISM) band cause interferences and demands for intelligent interference avoidance schemes. This paper proposes a novel Diversified Adaptive Frequency Rolling (DAFR) technique for frequency hopping in Bluetooth piconets which has the tendency to mitigate both the self and static interferences and ensures sufficient frequency diversity. Simulation studies validate the prospects for the proposed scheme to be used for frequency hopping networks against already existing techniques, Adaptive Frequency Hopping (AFH) and Adaptive Frequency Rolling (AFR).

본 논문에서는 MICS(Medical Implant Communication Service, 402~405 MHz)와 ISM(The Industrial, Scientific and Medical, 2.40~2.485 GHz) 대역에서 동작하는 의료용 무선 중계 시스템을 위한 이중 대역 인체 부착형 안테나를 제안하고, 인체의 영향을 고려한 안테나 성능에 대한 분석을 하였다. 제안된 안테나는 ISM 대역에서 동작하는 윗면의 패치와 MICS 대역에서 동작하는 바닥면의 패치로 구성되어 있다. 안테나가 실제 인체에 착용되어 사용되는 상황을 고려하고, 인체가 안테나에 미치는 영향을 분석하기 위하여 모의 인체를 이용하여 시뮬레이션과 측정을 수행하였다. 제안된 안테나의 반사 손실은 MICS 대역과 ISM 대역에서의 요구 대역폭을 만족하였고, 측정된 최대 이득은 MICS 대역과 ISM 대역에서 각각 -12.47 dBi, 1.71 dBi이었다. 제안된 안테나의 방사 패턴은 MICS 대역에서 인체 내부 지향성, ISM 대역에서 인체 외부 지향성을 가지며, 반사 손실 특성은 인체의 영향에 매우 둔감하므로 의료용 무선 중계 시스템용 인체 부착형 안테나로 활용되기에 적절할 것으로 사료된다. In this paper, a dual-band on-body antenna operating at MICS and ISM band for a wireless medical repeater system is proposed and the antenna performance including the human body effect is investigated. The designed dual-band antenna is comprised of a top patch for ISM band and bottom patch for MICS band. Simulation and measurement was carried out in order to analyze the effects of human body on antenna performance considering real use. The proposed antenna has required impedance bandwidth enough to cover both MICS and ISM bands. The measured peak gains were -12.47 dBi and 1.71 dBi at the each center frequency of MICS and ISM bands, respectively. Furthermore, the antenna has the maximum radiation directed toward the inside of the human body in the MICS band and directed toward the outside in the ISM band. In addition, the return loss property of the antenna is insensitive to human body effects so that the proposed antenna is well suited for the on-body wireless medical repeater system.

Wearable textile antennas have gained significant attention in recent years due to its growing demand.They are portable and integrating these antennas into textiles enhance wearability and comfort. In this project we explore the design and optimization of a horn-shaped wearable textile antenna for resonance in the ISM (Industrial, Scientific, and Medical) band and diverse commercial wireless applications.The antenna will be designed on a jeans substrate with a relative permittivity (εr) of 1.6 and having physical dimensions of 50×80×0.56 mm3. In terms of performance, the proposed antenna will be analyzed by observing the parameters like Return loss,Gain and VSWR.These wearable antennas are used in medical field to remotely monitor the blood pressure,heart rate and temperature of the patient.This antenna also works for WiFi,WiMAX,ISM and C-band applications.The desired antenna will be simulated using CST Microwave Studio. . Keywords— Microstrip patch antenna, ISM band, Multiband.

In May, 1985, the Federal Communications Commission (FCC) allowed the unlicensed use of spread spectrum (SS) in the Industrial, Scientific and Medical (ISM) band for commercial transmission without the need for a license as long as the user follows certain guideline in terms of transmission power level. The scarcity of communication bandwidth has lead researchers to investigate algorithms to identify busy channels over the airwave so they can be avoided and not add to communication degradation. This is very salient in the over used ISM band. In the ISM band the solution lies in developing efficient algorithms to detect which parts of the band are being used and utilize an agile communication system to hop to the available parts which support good communication. In addition, a solution of this nature can find application in electronic warfare, where fire fighters in the field would like to identify enemy attacks on their frequency hop spread spectrum (FHSS) channels and take appropriate measures to protect their communication channels from a jammer's interference. This paper is based on a scaled down version of the Bluetooth FHSS channel model. It proposes the use a polyphase channelizer to identify an active channel.

The 2.4 GHz industrial, scientific and medical (ISM) band is a shared electromagnetic resource where many wireless communications technologies such as wireless local area networks, Bluetooth, ZigBee, cordless phones, amongst others, coexist. Due to the large amount of users of different technologies that might utilize the band at the same time and geographical region, it is reasonable to assume that the band is very busy all the time. In this paper, however, a spectrum measurement campaign is carried out to determine the actual spectrum occupancy of the ISM band in an environment with high density of users. Although many wireless technologies share this frequency band, results show its low spectrum utilization. Indeed, it is shown that the spectral occupation of the band ranges between 7% and 34% of a normal working day, and it is moderate even during busy hours. Therefore, the use of a more sophisticated approach is essential to exploit the unlicensed access to this band, for which cognitive radio is well suited. This is valid despite the fact that, formally speaking, there are no licensed (or primary) users in the ISM band. Nevertheless, ISM users could be treated as pseudo-primary. Thus, cognitive radio techniques can be implemented to improve the spectrum utilization.

In this paper, an adaptive and self-organizing spectrum allocation policy for ad hoc femtocells in two-tier networks based on usage of random frequency hopping is presented. As femto- and macrocells normally share the same frequency resources, the proposed approach is able to minimize InterCell Interference (ICI) in an adaptive manner. Each femto- and macrocell user chooses random carrier frequencies for transmission corresponding to a given probability density function (pdf). If the level of interference reaches a certain limit, which is typically the case for femtocell edge users, the probability density function of the carrier frequencies is changed in a way that it is quasi-orthogonal to the one of the macrocell users nearby. The changeover point between different probability density functions is realized in a self-organizing manner regarding the detected level of interference. Hence, the approach is able to adjust the trade-off between spectral efficiency and introduced interference during operation. We present analytical models for the Signal-to-Interference-and-Noise-Ratio (SINR), the Bit Error Ratio (BER) and the required transmission power of Orthogonal Frequency Division Multiple Access (OFDMA) femtocells applying adaptive random frequency hopping. The mobile radio channel is characterized by non-frequency selective Rayleigh fading and all results are verified by simulations implemented in MATLAB. In order to evaluate the improvements, the results are compared to systems using centralized orthogonal planning, systems using neither centralized nor distributed planning, and systems using static random frequency hopping. The comparison shows that adaptive random frequency hopping is capable of reducing the BER by a factor of 15 and the transmission power of femtocells by 17 dBm compared to systems where the macrocell user transmits in the same subbands as the femtocell user.

In this paper we present the multi-frequency wireless communication protocol and adaptive frequency hopping algorithm that are designed specifically with the goal of increasing the reliability of the physiological data transmissions by medical body area networks (MBAN). We discuss the protocol structure and compare adaptive and non-adaptive frequency hopping algorithms used within the MAC protocol. We introduce the comprehensive simulation framework and provide the simulation results which clearly show the advantage of using adaptive frequency hopping in realistic hospital scenarios, dominated with inter-MBAN and Wi-Fi interferes.

A textile, embroidered antenna, based on the fractal shape of the Sierpinski triangle, is designed in this paper for operation in the European free Industrial Scientific and Medical (ISM) 863–870 MHz band, as well as in the 902–928 MHz band designated for ISM applications in North and South America. Several prototypes have been fabricated by employing different stitch patterns and thread materials. The effect of the fabrication parameters on the performance of the proposed antenna is investigated through measurements and simulations, with the results being in good agreement. The antenna exhibits attractive characteristics such as wide bandwidth, relatively stable radiation patterns, as well as robustness in washing. Several tests reveal that convex and concave bent conditions do not affect the coverage of the aforementioned ISM bands, despite the shift of the resonant frequency in some cases. Moreover, the SAR values resulting from simulations are below the corresponding thresholds suggested by international guidelines.

Wireless technology has become an invaluable facilitator in many aspects of daily life. Healthcare environments in particular have gained noticeable agility and flexibility by integrating wireless functionality into various medical equipment. As of late, chipsets designed to implement communication standards in the Industrial, Scientific and Medical (ISM) band have become inexpensive and widely available, making wireless-enabled medical devices reach increased number of users. However, the sharp increase in the number of operating nodes now occupying the ISM band has resulted in a cluttered spectrum with limited resources in many environments. In this paper, we report on a long term spectrum survey of the ISM band in both an intensive care unit (ICU) and a post-surgery recovery room (RR). Both spaces were concurrently surveyed for 28 consecutive days capturing spectrum occupancy on every weekday four times. Results indicate that spectrum occupancy patterns are location dependent. Examined sub-channels with significant correlation in activity pattern corresponded mainly to IEEE 802.11 channels 1, 6, and 11. Low daily duty cycle is indicated at a maximum of 5.17% at RR and 3.11% at ICU.

In this paper, we propose a slotted adaptive frequency hopping and rolling (SAFHR) scheme to realize the dynamic spectrum access for cognitive radio (CR). First, based on the CR spectrum sensing result and the quadratic prime code, an adaptive frequency hopping scheme is designed to avoid the frequency static interference due to primary user (PU). Secondly, adaptive frequency rolling scheme is incorporated to combat the frequency dynamic interference in the presence of multiple CR nets. As a whole, the SAFHR algorithm aims to maximize the frequency spectrum utilization and frequency diversity for each CR user, and to accommodate as many CR users as possible. By employing a so called Instruments-in-MATLAB software defined radio (IM-SDR) platform, experimental results of the SAFHR scheme is demonstrated under the scenario with two CR nets, five CR nodes, and one PU.

Wireless systems using low-power wireless communication protocol are rapidly gain popularity in the license-free industrial scientific, and medical (ISM) frequency bands. One such emerging trend in ISM frequency bands is home automation. Historically, all the home devices were once unconnected, today are now being connected either by a wired or wireless connection. The low-power wireless communication protocols enable integration of all the digital home devices into a single system and enhance end user product experience. The rapid prototyping of these end user product using programmable radio system such as software-defined radio (SDR) has been the game-changer in the field of home automation. In this article, we present an overview of popular ISM bands in different regions of the world. Furthermore, we analyze the signals from the wireless electric switch using a software-defined radio in 433 MHz ISM band.

The proposed implantable CPW fed monopole slot antenna for industrial scientific and medical (ISM) band biomedical applications of dimension 25mm × 16mm × 0.5mm at ISM band (2.4 – 2.48 GHz) and short distance communication band (Electronic Communications Committee approved the frequency band 688 MHz). The antenna is placed on human tissues like skin, fat, muscle, etc and it is made compatible for implantation by embedding it on FR4 substrate. These Implantable CPW fed monopole slot antennas are significantly used in implantable biomedical devices due to the merits such as flexibility in design, conformability, size, safety and low power consumption.

This paper comes with a new study on the conception of a CPW-Fed multi bands planar antenna. The design takes into account that this structure can be integrated with circuits behind, that why the Fed is a CPW one. The antenna validated is suitable for GSM, DCS and ISM band. The entire area of the antenna is 36×72.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and it is printed on an FR4 substrate. The printed U-shaped antenna is formed from two horizontal arms of different lengths and an L-shaped shorted strip which is connected between the vertical arm and the ground plane. The antenna is designed, optimized, and miniaturized by using ADS "Advanced Design System" and the results are compared with CST Microwave Studio.

Intraoral tongue drive system (iTDS) is a promising assistive technology for rehabilitating disabled persons. This article proposes a radiative near field power transfer (RNF-PT) system comprising an intraoral differential rectenna (rectifying antenna) and external power transmitter (RNF-Tx). A dual-band compact differential intraoral antenna operating in the Industrial, Scientific and Medical (ISM) band (2.45 GHz) and midfield band (1.9 GHz) is proposed for the data and power transmission modes, respectively. The proposed differential antenna and rectifier were designed and fabricated individually using a Rogers RT/duroid 6010 substrate. The differential rectifier shows a simulated conversion efficiency of 89.3% for a radio frequency (RF) input power of 14.78 dBm at 1.9 GHz with a 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{k}\Omega $ </tex-math></inline-formula> load. The maximum transmission coefficient of −25.95 and −24.93 dB was achieved at a separation of 22 mm for the closed and opened mouth conditions, respectively. The measured impedance bandwidths of the proposed antenna in both the closed and open mouth of the test subject are around 10% in the midfield band and around 9.5% in the ISM band, respectively. The measured peak gain in the minced pork and saline solution was −20.48 dBic, −18.25 dBic at the frequency of 1.9 GHz and −18.54 dBi, and −16.88 dBi at the frequency of 2.45 GHz, respectively. The specific absorption rate (SAR) values have also been analyzed through simulations for both data and power transmission modes and are found acceptable in the closed and open mouth placements. Based on these acceptable SAR values, the link margin was theoretically calculated where it could communicate over a reasonable distance. Thus, the proposed intraoral differential antenna with a rectifier is ideal for data and PT support in iTDS-based applications.

In this paper, a novel voltage controlled oscillator (VCO) with low phase noise, low power consumption and wide tuning range in the industrial, scientific and medical (ISM) band is proposed for communication systems applications. For improving the phase noise, filtering technique is used and VCO is designed with TSMC CMOS 0.18 μm technology and the power supply is 1.5 V. The simulation results with advanced design system (ADS) shows that phase noise in 1 MHz offset frequency from the carrier is -122 dBc/Hz and tuning range is 2 to 2.8 GHz. The power consumption of the core is 2.49 mW.