Wireless intraoffice networks

Int J Wireless Inf Networks

Krishnamurthy

2020

106

The IEEE 802.11 standard for wireless local area networking (WLAN), commercially known as Wi-Fi, has become a necessity in our day-today life. Over a billion Wi-Fi access points connect close to hundred billion of IoT devices, smart phones, tablets, laptops, desktops, smart TVs, video cameras, monitors, printers, and other consumer devices to the Internet to enable millions of applications to reach everyone, everywhere. The evolution of Wi-Fi technology also resulted in the first commercial piloting of spread spectrum, high speed optical communications, OFDM, MIMO and mmWave pulse transmission technologies, which then became more broadly adopted by cellular phone and wireless sensor networking industries. The popularity and widespread Wi-Fi deployment in indoor areas further motivated innovation in opportunistic cyberspace applications that exploit the ubiquitous Wi-Fi signals. The RF signal radiated from Wi-Fi access points creates an "RF cloud" accessible to any Wi-Fi equipped device hosting or supporting these opportunistic applications. Wi-Fi positioning and location intelligence were the first popular opportunistic applications of Wi-Fi's RF cloud. Today, researchers are investigating opportunistic applications of Wi-Fi signals for gesture and motion detection as well as authentication and security. This paper provides a holistic overview of the evolution of Wi-Fi technology and its applications as the authors experienced it in the last few decades.

Section: The Origin Of Wlan Technologies Before 1985mentioning

confidence: 99%

Evolution and Impact of Wi-Fi Technology and Applications: A Historical Perspective

Int J Wireless Inf Networks

Krishnamurthy

2020

106

“…The system ( (4) and A is the amplitude of the transmitted signal. The chip duration.T, is 1/W, W being the available bandwidth.…”

Section: A Transmittermentioning

confidence: 99%

“…For random To combat the BER degradation, various anti-multipath modulation schemes, in which a redundant phase/amplitude transition is imposed on a basic conventional modulation, have been proposed [4]-[SI. In a DSK [4] scheme, a phase-jump, the direction of which has the same binary information as symmetric BPSK, is repeated twice for every information bit. In an SPSK [7] scheme, a phase-jump is redundantly imposed on the DPSK timeslot.…”

Section: Appendix B (A231mentioning

confidence: 99%

“…In the U.S. the FCC has assigned three bands for nongovernmental applications of spread spectrum which enhance this alternative for indoor channels [3]. The only reservation concerning DS-CDMA communications is the efficiency of the bandwidth utilization in fading multipath channels [4]. Coding and diversity combining can improve the bandwidth efficiency of DS-CDMA communications [5]- [7].…”

Section: Introduction He Increasing Popularity Of Portable Personamentioning

confidence: 99%

See 1 more Smart Citation

Performance of DS-CDMA over measured indoor radio channels using random orthogonal codes

Chase¹,

IEEE Trans. Veh. Technol.

1993

Self Cite

Direct sequence spread spectrum, with its inherent resistance to multipath interference, has become a commercial reality for indoor wireless communications and has been proposed for personal communication networks. To allow multiple users within the limited bandwidths allocated by the FCC, codedivision multiple-access (CDMA) is needed. This paper analyzes the performance of CDMA systems using random orthogonal codes over fading multipath indoor radio channels using channel measurements from five different buildings. The effect of RAKE receiver structure is studied, as is the effect of average power control. The average probability of error as a function of signalto-noise ratio is used as the performance criteria. Results are compared with models for Rayleigh fading channels. width efficiency of M-ary orthogonal codes over nonfading channels is discussed in [9], and over fading channels in [lo]. This paper analyzes such a system using measured multipath fading channel data. The particular examples use the measured multipath characteristics from five manufacturing areas [ 111 and a bandwidth permitted by the FCC [3]. A RAKE receiver structure is investigated and compared with theoretical results for Rayleigh fading channels.

“…The holistic view of wireless data communications for office information networking emerged in the mid-1980's [1], [2] and the IEEE 802.11 standardization activity for wireless local area networking, commercially known as Wi-Fi, began in late 1980s to address this industry. Today, when we arrive at a hotel registration desk, the first fundamental questions we ask related to our basic needs are: Where is my room?…”

Section: Introductionmentioning

confidence: 99%

RF Cloud for Cyberspace Intelligence

Ying

et al. 2020

IEEE Access

Wireless information networks have become a necessity of our day-today life. Over a billion Wi-Fi access points, hundreds of thousands of cell towers, and billions of IoT devices, using a variety of wireless technologies, create the infrastructure that enables this technology to access everyone, everywhere. The radio signal carrying the wireless information, propagates from antennas through the air and creates a radio frequency (RF) cloud carrying a huge amount of data that is commonly accessible by anyone. The big data of the RF cloud includes information about the transmitter type and addresses, embedded in the information packets; as well as features of the RF signal carrying the message, such as received signal strength (RSS), time of arrival (TOA), direction of arrival (DOA), channel impulse response (CIR), and channel state information (CSI). We can benefit from the big data contents of the messages as well as the temporal and spatial variations of their RF propagation characteristics to engineer intelligent cyberspace applications. This paper provides a holistic vision of emerging cyberspace applications and explains how they benefit from the RF cloud to operate. We begin by introducing the big data contents of the RF cloud. Then, we explain how innovative cyberspace applications are emerging that benefit from this big data. We classify these applications into three categories: wireless positioning systems, gesture and motion detection technologies, and authentication and security techniques. We explain how Wi-Fi, cell-tower, and IoT wireless positioning systems benefit from big data of the RF cloud. We discuss how researchers are studying applications of RF cloud features for motion, activity and gesture detection for human-computer interaction, and we show how authentication and security applications benefit from RF cloud characteristics.