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WirelessHART, The Leading Technology for Industrial Wireless Networked Control Systems
Published in Tran Duc Chung, Rosdiazli Ibrahim, Vijanth Sagayan Asirvadam, Nordin Saad, Sabo Miya Hassan, TM, 2017
Tran Duc Chung, Rosdiazli Ibrahim, Vijanth Sagayan Asirvadam, Nordin Saad, Sabo Miya Hassan
As described earlier, the DSSS helps spread the communication frequencies over a range around 2,450 MHz, thus resulting in multiple channels at different frequencies for more possible network links and improved communication reliability in the network. With self-healing and self-organizing capabilities [53], and ability to support update rates of less than 1s, which is sufficient for automated process application, a WirelessHART network can support up to hundreds or thousands of devices. Furthermore, it supports star topology to maximize a device’s battery lifetime and mesh topology to improve a network’s reliability and coverage. By utilizing advanced encryption standard (AES) 128 encryption mechanism, WirelessHART communication is secured [51]. However, currently, its application is mainly for process, equipment and environment monitoring, asset management, and advanced diagnostics but not for control [53]. A typical WirelessHART network is shown in Figure 2.4. The network consists of a host application, a gateway serving as network manager and security manager, an access point and three field devices (Node 1 to Node 3) [20].
Jamming Attacks and Countermeasures in UAV Networks
Published in Fei Hu, Xin-Lin Huang, DongXiu Ou, UAV Swarm Networks, 2020
Delwar Hossain, Qian Mao, Immanuel Manohar, Fei Hu
Direct Sequence Spread Spectrum (DSSS) and frequency hopping spread spectrum (FHSS) are used to defend from jamming attacks. For signal transmission, DSSS provides wider bandwidth while FHSS offers meddling avoidance. A hybrid scheme, called Hermes node, is anticipated to deal with jamming attacks. The node of Hermes performs 1,000,000 hops per second (FHSS) to evade the jammers. DSSS can make the attacker sense the data signals as white noise, which averts the detection of the communication radio band. Synchronization between nodes is important for the Hermes node to work properly, which is achieved by the sink [28, 35].
Wireless LANs
Published in Jerry D. Gibson, The Communications Handbook, 2018
Spread spectrum transmission technology is used for RF-based LANs and it comes in two varieties: direct-sequence spread spectrum (DSSS) and frequency-hopping spread spectrum (FHSS). In a FHSS system, the available band is split into several channels. The transmitter transmits on one channel for a fixed time and then hops to another channel. The receiver is synchronized with the transmitter and hops in the same sequence; see Fig. 85.2(a). In DSSS systems, a random binary string is used to modulate the transmitted signal. The relative rate between this sequence and user data is typically between 10 and 100; see Fig. 85.2(b).
Detection of Power Theft in Low Voltage Distribution Systems: A Review from the Indian Perspective
Published in IETE Journal of Research, 2022
Arvind Kumar Gupta, Aurobinda Routray, VN Achutha Naikan
We are currently encountering the fourth Industrial Revolution regarding the cyber-physical system. Adoption and coordination of the Internet of things (IoT) into the industrial chain has formed the foundation for the next industrial revolution [99]. So, the use of IoT for the prevention of power theft will be a good solution [100, 101]. We can use Wi-Fi technology, which is a universal wireless standard that enables smart gadgets to work together. It is widely used in commercial and industrial applications because of its benefits and intended to exchange data through a hostile RF environment. Incorporating the facilities like direct sequence spread spectrum, low duty cycle, low latency, encryption of data, and supporting multiple network topologies is simpler as well as easier with Wi-Fi [102]. It is best suited for low cost and low power applications. Recent trends like automatic meter reading, smart grid, smart energy, and lighting control use Wi-Fi for controlling purposes. It enables to get high performance with ultra-low power with the help of a smart RF transceiver. We can also track the energy consumption per group, per sector, and regional set-up needs to be structured, and the meter needs to be assessed statistically. In order to support the minimization of non-technical losses through statistical evaluation, the advancement of electricity meters must also be carried out to meet the standard accuracy [59, 63]. Following measures may also prevent energy theft.
Health effects of WiFi radiation: a review based on systematic quality evaluation
Published in Critical Reviews in Environmental Science and Technology, 2022
Stefan Dongus, Hamed Jalilian, David Schürmann, Martin Röösli
In order to represent a realistic WiFi signal, studies had to address exposure in the RF-EMF frequency range labeled as any of the IEEE WLAN 802.11 standards (e.g. 802.11ac, 802.11n, 802.11a, 802.11 b, 802.11 g, 802.11 h). If not specifically labeled, studies with realistic WiFi-like signals had to be in the frequency range of 2.400- 2.483 and/or 5.150 − 5.725 GHz and fulfill any of the following criteria:Signal was not a continuous wave (CW) signal, and was declared as a packet-type of data service.Modulation was described as direct sequence spread spectrum (DSSS), frequency-hopping spread spectrum (FHSS) or orthogonal frequency division multiplex (OFDM) resulting in stochastic signal characteristics with a pulse rate between 10 Hz for beacon only and ca. 100 Hz at maximum data transmission rate (Schmid et al., 2020).In the absence of data transmission, a pulse rate of 10 Hz was applied.Signal originated from a commercially available access point or mobile terminal (e.g. laptop).
Lattice-Based Coding to Enhance Error Performance of the Hidden Direct Sequence Spread Spectrum
Published in IETE Journal of Research, 2021
Nader Sanandaji, Abolfazl Falahati
Direct Sequence Spread Spectrum (DSSS) is known to be an effective method to reduce the influence of deliberate interferences and enhance the physical layer security of a communication system [1]. Such interferences are classified as “Denial of Service (DoS)” attack. Enhancing the error performance against this attack is regarded as a major task of a system physical layer security. The received message error probability is the main figure of merit with respect to this objective. On the other hand, improving the security against eavesdroppers is also another role of a DSSS system. To maintain the required security, spreading sequence exploited in the DSSS should be generated in a manner that it cannot be determined by any interferer or eavesdropper. This issue can be attained by employing chaos-based methods and pseudo-random sequence generation schemes that are fully discussed in [2].