Planar Inverted-F Antennas for Small Multi-Standard Handsets

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.

An adaptive bluetooth packet selection and scheduling scheme in interference environments

The explosive growth of the Internet over the last decade has led to an increasing demand for high-speed, ubiquitous Internet access. Broadband wireless technologies are increasingly gaining popularity by the successful global deployment of the wireless personal area networks (Bluetooth-IEEE 802.15.1), wireless local area networks (WiFi- IEEE 802.lln), and wireless metropolitan area networks (WiMAX- IEEE 802.16). New ICT and e-Learning strategies and advances in wireless standards and technologies- particularly in the areas of Bluetooth, WiFi (wireless fidelity), WiMAX (worldwide interoperability for microwave access) and mobile computing can help to bridge the digital divide in education and research. Using open broadband Wireless technologies and implementing mobile computing architectures, one can overcome the challenges of ground, infrastructure, and finance to increase access; deploy broadband quickly and cost-effectively to areas currently not served; and extend the benefits of digital revolution to previously unreachable populations. These technologies aim to provide low-cost, high-performance Wireless access to residential and business applications. As technology evolves to address portable and mobile applications, the required features and performance of the system will increase. Evolution toward the phase called "full mobility" provides incremental support for low latency, low packet loss and real-time handoff of subscriber terminals operating at high speeds. This paper presents the analogy of promising wireless technologies on different frequencies: Bluetooth, WiFi, and WiMAX. This paper is organised into four parts: part I describes the functionality and usage of Bluetooth in the wireless personal area networks, part II presents the WiFi- IEEE 802.1 In strategies for users considering higher-bandwidth alternatives to existing wireless personal area networks, part III discusses how the WiMAX is used as a current standard for Wireless data transmission technology, which is optimized to deliver high, bursty data rates to mobile subscribers, and to support real-time multimedia and Voice over IP (VoIP) applications, and part-TV explores how these emerging Wireless technologies differ from one another.

Problem statement: In universal networking environments; two or more heterogeneous communication systems coexisting in a single place. Especially, Wireless Local Area Networks (WLANs) based on IEEE 802.11b specifications and Wireless Personal Area Networks (WPANs) based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM) band. If the WPAN communication coverage is expanded using a cluster-tree network topology, then the 802.15.4 network is more susceptible to interference from neighboring WLANs. Approach: In this study, we propose an adaptive transmission power aware cluster scheduling algorithm using multiple channels in a WPAN in the presence of WLAN interference. Results: The algorithm includes node identification, channel allocation, clustering and time scheduling. To evaluate the performance of the proposed algorithm, the performance metrics such as Bit error, Packet Error Rate (PER), Throughput, Average End-End Delay and Average Jitter is measured through Qualnet simulation. PER is calculated from bit error rate. The simulation results are compared with the conventional TDMA scheme. Conclusion/Recommendations: The measurement result shows that the proposed algorithm is effective in an IEEE 802.15.4 cluster-tree network in the presence of multiple IEEE 802.11 interferers.

A very-low-profile, tri-band, planar inverted-F antenna (PIFA) with a height of 3.7 mm only for wireless local area network (WlAN) applications in the 2.4 GHz (2400~2484 MHz), 5.2 GHz (5150~5350 MHz), and 5.8 GHz (5725~5825 MHz) bands for tablet-laptop computer with a metal back cover is presented. The antenna was made of a flat plate of size 18.7 mm × 32.5 mm and bent into a compact structure with the dimensions 3.7 mm × 7 mm × 32.5 mm. The PIFA comprised a radiating top patch, a feeding/shorting portion, and an antenna ground plane. The top patch was placed horizontally above the ground with the feeding/shorting portion connecting perpendicularly therebetween. The antenna was designed in a way that the radiating patch consisted of three branches, in which each branch controlled the corresponding resonant mode in the 2.4/5.2/5.8 GHz bands.

Millimeter-wave (mmWave) communication standards in the unlicensed band—such as IEEE 802-based wireless personal area networks (WPANs), wireless local area networks (WLANs), and 3GPP-led cellular networks (CNs)—have faced challenges in achieving commercial acceptance for over a decade. To enable widespread adoption of mmWave communication systems, a concept called the mmWave virtual community network (VCN) has recently been proposed. In this architecture, a decentralized WPAN-style device-to-device (D2D) community coexists with centralized WLANs and CNs in the unlicensed mmWave band via multi-hop links. However, the current mmWave VCN concept lacks a clear definition of strategic and technical enablers to support large-scale commercial deployment. To address this gap, this paper proposes a strategic ecosystem that promotes mmWave VCN deployment for the mutual benefit of both decentralized and centralized entities. Specifically, the decentralized community—enabled by mmWave D2D communication—supports the coverage expansion of mmWave WLANs and CNs. In return, the CN operator incentivizes distributed communities through a reward mechanism, ensuring mutual growth and cooperation. Furthermore, we propose “New Radio Sidelink for mmWave Unlicensed (NR SL-mmW-U),” as a technical enabler of mmWave D2D communication, thereby materializing a sidelink-native mmWave VCN with concrete specifications. We evaluate the proposed sidelink-native mmWave VCN via a link-level simulation and initial incentive theory-based analytical model, thereby providing preliminary assessments of its feasibility in meeting the key requirements for realizing the envisioned ecosystem.

Multimedia applications place high demands on resources in wireless networks. The 60GHz frequency band has been adopted to support high data rate applications in wireless personal area networks (WPANs). In the IEEE 802.15.3c standard for millimeter-wave-based high-rate WPANs, devices are allocated a dedicated transmission time called a CTA (channel time allocation) based on their request to transmit. While the duration of a CTA may be adjusted, the standard does not specify how resource allocation should be achieved. High-Definition (HD) video with variable bit rate (VBR) is a potential application for the WPAN. In this work, an IEEE 802.15.3c network is simulated and the throughput losses due to static resource provisioning for a series of H.264/SVC (MPEG-4 Part 10) HD video sources are identified. It is demonstrated that the high data rates proposed for the 60GHz frequency band will not be achieved without dynamic resource allocation.

Interference among different wireless devices operating in the same frequency band in a given region is always a problem. The prominent type of it is the interference between Wireless Local Area Network (WLAN) and Wireless Personal Area Network (WPAN) devices operating in the 2.4-GHz unlicensed band. Various techniques such as Adaptive Frequency Hopping (AFH) were proposed recently to deal with this interference. When wireless devices are deployed on plant-floors, the approach required to mitigate the interference can be slightly different so that the proposed techniques should be able to support data prioritisation in addition to managing the interference. This will allow the important data through even if the interference levels are higher than expected. For this to take place, channel assessment should be done first, to find out which channels are suffering interference, to what levels and how often. This aspect of channel assessment is considered here, for different combinations of interferers and power levels.

ABSTRACTA microstrip patch antenna array has been designed with 24 ultra‐wide patch elements to improve the antenna gain up to around 20 dBi for 60 GHz band point to point wireless local area network (WLAN) and wireless personal area network (WPAN) applications. Both series and parallel feeding techniques have been collaborated to excite the patch elements. Reverse impedance matching method has been adopted to enhance the antenna's fabrication tolerance. The measured and simulation results showed a close agreement. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:511–514, 2017

Body-centric wireless communications (BCWCs) have received increasing attention due to its potential application in areas such as E-health systems, home care, security, and entertainment. A compact and low-profile wearable planar inverted-F antenna (PIFA) with tuning function is presented for BCWCs in this paper. A two-thirds muscle-equivalent phantom is used to model the human's arm. By tuning the proper capacitance of the proposed antenna, the industrial, scientific and medical (ISM, 2.40–2.48 GHz), wireless broadband (WiBro, 2.3–2.39 GHz) and Universal Mobile Telecommunications System (UMTS, Rx 2.1–2.17 GHz) and meanwhile lower band can also cover 950–956 MHz.

This paper shows measurements of the shielding effectiveness of two commonly used building materials, wood and marble. Of specific interest is the shielding effectiveness of these materials in the 900MHz and 2.4GHz regions, the operating frequencies of ZigBee, wireless personal area networks and wireless local area networks. A relatively new method for shielding effectiveness using the reverberation chamber is adopted in this paper and some shortcomings are presented. This paper aims to assist service providers in making power budget estimates.

The demand for increasingly higher rates of data, voice, and video transmission, together with miniaturization of portable and wireless technologies, has driven the need for high-performance applications that have become a major aspect of every day life. From hundreds of megahertz to millimeter-wave frequencies, the evolution of wireless communications has led to several indispensable technologies such as cellular communications, wireless local area networks (WLAN), ultra-wideband (UWB), and wireless personal area networks (WPAN). Consumer driven, the need for accessing these radio technologies has been pushing radio-frequency (RF) engineers toward achieving low-cost and ultraminiaturized solutions. With the need for more flexible, light weight, and reconfigurable systems, these solutions are beginning to have an impact on space and defense applications as well.

OFDM is a multicarrier modulation technique which is used in communication systems like Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Metropolitan Area Network (WMAN), Wi-Max, DVB-T etc for the high rate transmission over wireless radio channels. It is commonly known as a transmission technique of high spectral efficiency and robustness against frequency selective fading. The advantages of OFDM include simple digital realization, compatibility with multipath fading channel, less complex receivers and improve the bandwidth efficiency. At the same time, it also increases system capacity providing reliable transmission. But the main problem of OFDM systems is Peak to average power ratio due to its envelope fluctuation. The objective of this project this to provide a broader understanding in peak-to-average power ratio (PAPR) problem in orthogonal frequency division multiplexing (OFDM) systems. This paper showcases main three reduction techniques, precoding and SLM in combination with nonlinear companding in detail considering advantages and disadvantages of each technique.

A compact dual-band Planar Inverted-F Antenna (PIFA)\n\nworking in both the DVB-T (Digital Video Broadcasting-Terrestrial) and\n\nthe WLAN (Wireless Local Area Network) IEEE 802.11b,g frequency\n\nbands is presented. It is designed to be integrated in a monitor-equipped\n\ndevice, and exhibits reduced electrical size with respect to similar PIFA\n\nconfigurations. A reflection coefficient less than 6 dB and 10 dB\n\nwas obtained in the 470–862 MHz (59% percentage bandwidth) DVB-T\n\nand the 2400–2484 MHz (2.7% percentage bandwidth) WLAN bands,\n\nrespectively. An antenna gain of almost 3 dBi and 4.5 dBi, with more than\n\n95% radiation efficiency, was obtained in the two frequency bands of\n\ninterest. The PIFA fills an overall volume of and can\n\nbe realized by a properly cut and fold single metal sheet. Measurements\n\non prototypes have shown that the proposed layout is robust in terms of\n\nthe impedance matching detuning that can be caused by the presence of\n\nmetal parts nearby the antenna.

Scatternet formation is one of the most important issues of emerging wireless personal area networks (WPANs). Numerous papers pointed out that the performance of a WPAN highly depends on the scatternet structure; however, for next generation WPANs (IEEE 802.15.3 and 802.15.4) the issue of scatternet formation is not discussed in the literature so far. This paper presents the techniques, constraints and effects of scatternet formation. First, the theoretically based problem is formulated in integer linear programming (ILP) framework. Two heuristic methods are proposed for high-rate WPANs (802.15.3), which can be extended for low-rate WPANs (802.15.4) as well. The constructed networks are analyzed based on two metrics: (1) total network load, (2) amount of piconets. We show that network performance highly depends on the used algorithm: the network load can be reduced by up to 30% by using a proper scatternet formation algorithm. Furthermore, the scatternet can be optimized depending on the actual network traffic and individual objectives