COSFI-RIMAC: A Cooperative Short Frame Identifier Receiver Initiated MAC protocol for Wireless Sensor Network

Power consumption is the most important factor to evaluate the performance of Wireless Sensor Networks (WSNs). Most sensor network Medium Access Control (MAC) protocols operate on the basis of a duty cycle mechanism. The asynchronous receiver initiated MAC duty cycle protocols are popular due to their relatively higher energy efficiency. However, recent advances harnessing the benefits of cooperative communication has become one of the solutions of MAC duty cycle protocol. In this article, we improve the RI-MAC protocol by introducing a short frame identifier to notify the sender when the receiver wakes up. This resolution reduces idle listening, which increases energy performance. When the sender node receives a short frame identifier, it cooperates with neighboring senders, which minimizes collisions.Our protocol is called: a Cooperative Short Frame Identifier Receiver Initiated MAC protocol, COSFI-RIMAC is an asynchronous MAC protocol cooperative service cycle initiated by the receiver. The simulation result on the NS2 simulator shows that the COSFI-RIMAC mechanism reduces power consumption, produces minor latency and increases the rate of packet delivery.

Energy-Efficient Method for Wireless Sensor Networks Low-Power Radio Operation in Internet of Things

The radio operation in wireless sensor networks (WSN) in Internet of Things (IoT) applications is the most common source for power consumption. Consequently, recognizing and controlling the factors affecting radio operation can be valuable for managing the node power consumption. Among essential factors affecting radio operation, the time spent for checking the radio is of utmost importance for monitoring power consumption. It can lead to false WakeUp or idle listening in radio duty cycles and ContikiMAC. ContikiMAC is a low-power radio duty-cycle protocol in Contiki OS used in WakeUp mode, as a clear channel assessment (CCA) for checking radio status periodically. This paper presents a detailed analysis of radio WakeUp time factors of ContikiMAC. Furthermore, we propose a lightweight CCA (LW-CCA) as an extension to ContikiMAC to reduce the Radio Duty-Cycles in false WakeUps and idle listening though using dynamic received signal strength indicator (RSSI) status check time. The simulation results in the Cooja simulator show that LW-CCA reduces about 8% energy consumption in nodes while maintaining up to 99% of the packet delivery rate (PDR).

Game Theory and Queue Learning Based Sleep/Wakeup Approach Scheduling in Wireless Sensor Network for Energy Efficiency

Wireless Sensor Network (WSN) is a network with numerous sensor nodes for examining physical situations, communication and data collection. Sensor nodes communicate with a base station to distribute their data for the purpose of remote process and storage. While transmitting the data energy problem were occurred. This paper goal is to enables senders to predict receivers' wake-up times by using a reinforcement learning technique. If senders have packets to transmit, senders can wake up shortly before the predicted wake-up time of receivers, so the energy, which senders use for idle listening, can be saved. In this case, senders do not have to make the trade-off, because their wake-up times are totally based on receivers’ wake-up times. Receivers still face the trade-off, however, since a receiver’s wake-up time relies on our technique to scheduling function and different selections of parameters in this function will result in different wake-up intervals. In addition, before a sender can make a prediction about a receiver's wake-up time, the sender must request the parameters in the receiver’s wake-up scheduling function.

Advances and Opportunities in Passive Wake-Up Radios with Wireless Energy Harvesting for the Internet of Things Applications

Wake-up radio is a promising approach to mitigate the problem of idle listening, which incurs additional power consumption for the Internet of Things (IoT) wireless transmission. Radio frequency (RF) energy harvesting technique allows the wake-up radio to remain in a deep sleep and only become active after receiving an external RF signal to ‘wake-up’ the radio, thus eliminating necessary hardware and signal processing to perform idle listening, resulting in higher energy efficiency. This review paper focuses on cross-layer; physical and media access control (PHY and MAC) approaches on passive wake-up radio based on the previous works from the literature. First, an explanation of the circuit design and system architecture of the passive wake-up radios is presented. Afterward, the previous works on RF energy harvesting techniques and the existing passive wake-up radio hardware architectures available in the literature are surveyed and classified. An evaluation of the various MAC protocols utilized for the novel passive wake-up radio technologies is presented. Finally, the paper highlights the potential research opportunities and practical challenges related to the practical implementation of wake-up technology for future IoT applications.

Independent Biaxial Scanning Light Detection and Ranging System Based on Coded Laser Pulses without Idle Listening Time

The goal of light detection and ranging (LIDAR) systems is to achieve high-resolution three-dimensional distance images with high refresh rates and long distances. In scanning LIDAR systems, an idle listening time between pulse transmission and reception is a significant obstacle to accomplishing this goal. We apply intensity-modulated direct detection (IM/DD) optical code division multiple access (OCDMA) using nonreturn-to-zero on-off keying to eliminate the idle listening time in scanning LIDAR systems. The transmitter records time information while emitting a coded laser pulse in the measurement angle derived from the pixel information as the measurement direction. The receiver extracts and decodes the reflected laser pulses and estimates the distance to the target using time-of-flight until the pulse is received after being transmitted. Also, we rely on a series of pulses and eliminate alien pulses via several detection decision steps to enhance the robustness of the decision result. We built a prototype system and evaluated its performance by measuring black matte and white paper walls and assessing object detection by measuring a watering can in front of the black matte paper wall. This LIDAR system eliminated both shot and background noises in the reception process and measured greater distances with improvements in accuracy and precision.

An improved asynchronous energy-saving mechanism for IEEE 802.15.5-based networks

IEEE 802.15.5 standard introduces the mesh routing which improves reliability and robustness of routing in wireless sensor network since there are multiple routes from source node to destination node. To achieve energy efficiency for a long network lifetime, the asynchronous energy saving is proposed in IEEE 802.15.5, which includes the receiver-initiated unicast mechanism and the sender-initiated broadcast mechanism. In this article, an improved asynchronous energy saving named semi-synchronous energy saving is proposed to deal with the energy inefficiency from idle listening existing in asynchronous energy saving. In semi-synchronous energy saving, every node maintains the wake/sleep schedule information of nodes in its two-hop neighborhood and uses this information to calculate the wake-up time of an interested neighbor that the data will be sent to, which reduces idle listening time in both unicast and broadcast mechanisms. A low delay routing mechanism is also proposed based on the wake/sleep schedule information of neighbors. Furthermore, the optimal guard time to guarantee receiving the wake-up notification from neighbor in the presence of clock drift is investigated for saving energy. The performance analysis and simulation evaluation show that semi-synchronous energy saving saves more than 80% of energy with less than 30% memory cost compared to asynchronous energy saving, and it also improves the time of completing broadcast and the end-to-end delay.