Power-saving Scheme Research Articles

Dynamic Clock Switching Scheme for Enhanced Power Efficiency in System-on-Chip Architectures

High power consumption and thermal management are critical challenges in traditional System- on-Chip (SoC) architectures due to multiple active clock sources feeding individual IP blocks, even during idle states. This paper introduces a dynamic clock switching power-saving scheme that consolidates clock sources by dynamically switching to a single lower-frequency clock during low-power modes. A Clock Control Agent (CCA) monitors real-time operational status, power consumption, and performance needs, leveraging AI for predictive adjustments. Experimental results demonstrate a significant reduction in idle power consumption and improved thermal management, without compromising performance or data integrity. This scheme addresses inefficiencies in existing methods such as Dynamic Voltage and Frequency Scaling (DVFS) and clock gating, offering a robust and efficient solution for next-generation SoC designs.

A Power Saving Scheme for IEEE 802.15.3d THz Wireless Communication Links

Terahertz (THz) band spans the frequencies lying between 0.1 and 10 THz and represents the gap between millimeter waves and Infrared bands. THz will play an influential role in mitigating the spectrum resources shortage to meet the exponential growth of services and wireless devices. Standardization activities are being carried out to regulate the THz band's exploitation under the IEEE 802.15 standardization project. Despite the generous bandwidth, THz communications suffer from high pathloss and attenuation due to Molecular Absorption. As such, THz systems need to use extra power, suitable antennas, and enhanced signal processing and communication techniques to compensate for different signal attenuation sources. In this paper, we propose a new operation mode for the IEEE standard 802.15 to save the power transmission requirement while achieving the required data rate. Hence, less battery or antenna size is needed to support the same communication link quality. To this end, we optimize the power, modulation scheme, and channel allocation to minimize the total transmitted power keeping a minimum quality-of-service. Moreover, the design captures the effect of humidity on the system performance.

A review of energy saving routing schemes for WSN assisted IoT network

Abstract In WSN assisted IoT networks, the devices have to search the path up to the IoT hub for data transmission. Although the device’s hardware capabilities are increasing day by day, the device’s battery capacity is not increasing at the same rate. IoT devices have limited-power batteries that are not rechargeable. It is also challenging to replace their battery while the devices are in use. Moreover, we need advanced power-saving schemes to make these IoT technologies more adaptable. Due to the energy constraints and limited memory capacity of these IoT devices, we require more energy-efficient routing protocols to route data to the IoT hub. This paper has surveyed the most recent state-of-the-art routing protocol and highlighted their limits and path for future research.

Deep-Learning-Based Signal Enhancement of Low-Resolution Accelerometer for Fall Detection Systems

In the last two decades, fall detection (FD) systems have been developed as a popular assistive technology. To support long-term FD services, various power-saving strategies have been implemented. Among them, a reduced sampling rate is a common approach for an energy-efficient system in the real world. However, the performance of FD systems is diminished owing to low-resolution (LR) accelerometer signals. To improve the detection accuracy with LR accelerometer signals, several technical challenges must be considered, including mismatch of effective features and the degradation effects. In this work, a deep-learning-based accelerometer signal enhancement (ASE) model is proposed as a front-end processor to help typical LR-FD systems achieve better detection performance. The proposed ASE model based on a deep denoising convolutional autoencoder architecture reconstructs high-resolution (HR) signals from the LR signals by learning the relationship between the LR and HR signals. The results show that the FD system using support vector machine (SVM) and the proposed ASE model at an extremely low sampling rate (sampling rate < 2 Hz) achieved 97.34% and 90.52% accuracies in the SisFall and FallAllD data sets, respectively, while those without ASE models only achieved 95.92% and 87.47% accuracies in the SisFall and FallAllD data sets, respectively. The results also demonstrate that the proposed ASE mode can be suitably combined with deep-learning-based FD systems.

A Loading-Aware TDMA Sleep Scheme to Improve Power Consumption Performance on Medium to High Traffic for NG-EPON Networks

The inter-cycle sleep design previously proposed as a power-saving scheme for next-generation Ethernet passive optical networks (NG-EPONs) is able to effectively decrease the power consumption of heavy-load traffic. However, with a medium to high traffic load, these networks may still suffer from a high level of power consumption if no enhanced mechanisms are used. It was noted that the optical line terminal (OLT) often fully opens all communication channels at a medium to heavy load. Moreover, the number of opened channels was changed cyclically according to the traffic loading status. Accordingly, optical network units (ONUs) may be frequently allocated to different channels with changing loads. This may lead to inefficient operation and result in significant channel tuning delays. We thus propose a loading-aware time-division multiple access (TDMA) mechanism that allows the OLT to reserve a maximum bandwidth for each ONU when the network experiences heavy-load traffic. The performance results of our simulations reveal that the proposed scheme is able to reduce power consumption for targeted medium to high loads since ONUs under such loads can extend their sleep time because the cycle length is maximized. Moreover, the total delay is maintained at a relatively low level after applying the proposed scheme since the tuning delay is reduced significantly; however, the transmission delay is slightly increased due to the increased cycle length.

PARAMETER ANALYSIS OF SRAM CIRCUIT

The study examined the different a number of power-saving strategies, including sleep, stack, sleep stack, transmission gate logic, or self-controllable voltage level- upper (SVL-U). These methods are used with SRAM cells that have 6 transistors (6T), 7 transistors (8T), 8 transistors (9T), and 10 transistors (10T). The SVL-U method and transmission gate logic are used in suggested SRAM cell. According to a comparison of SRAM memory array as well as cells, dynamic power is significantly decreased on average when compared to traditional methods. The 45nm and 90nm software applications from Cadence are also used for simulation. According to a thorough analysis of SRAM memory arrays and cells, PDP and EDP have, on average, been significantly decreased when contrasted the state-of-the- art hybrid VLSI techniques. Therefore, these SRAMs are suitable for extremely low power embedded structural appliances. Keywords: Semiconductor Memories, Memory organization, SRAM, Write operation, Read Operation.

Introduction: On the Relevance of Arab Parliaments

Abstract This introduction leads into the Special Issue “Parliaments in the Middle East and North Africa: A Struggle for Relevance.” Parliaments in the Arab world have hardly been considered to be relevant institutions during the decades of authoritarianism in the post-independence era. If at all, they were of importance as a strategic element in the power-saving strategies of regimes. The “Arab Spring” ten years ago, with its loud calls for a more democratic and socially just political sphere, opened a new window of potentiality for the legislative chambers in the countries concerned, yet to very different avail: while the “Assemblée des Représentants du Peuple” in Tunisia gained unprecedented relevance as constitution-maker and governmental watchdog, the Egyptian Majlis al-Shaʿb was dissolved in 2012 after Islamists sweepingly won the elections and were reinstated only after the old forces had resecured their stark grip on power. Here, parliament has hardly gained any new relevance. This introduction outlines the core structure of the Special Issue which takes stock of parliaments in the Arab world a decade after the 2011 uprisings, discusses the state of research, and develops its guiding theoretic framework.

Power Saving Scheme for Process Corner Calibrated Standard Cell Based Flash ADC in Wireless Surveillance Applications

This paper proposes a power saving scheme to be used in standard cell based Flash ADC for wireless surveillance applications. The input signal to the wireless surveillance network has a very low activity during night time as compared to day time. Thus, the input signal rarely reaches voltage greater than a reference voltage $$V_Z$$ . The reference voltage $$V_Z$$ can be obtained by collecting a large number of light intensity samples during night time. The proposed power saving scheme uses an auxiliary standard cell comparator, whose switching threshold is kept equal to the reference voltage. The output of the auxiliary comparator disables a large number of comparator for all switching threholds greater than the reference voltage, thereby improving the power efficiency of the ADC. and simulated in a SCL 180 nm CMOS technology with a supply voltage of 1.8 V. The results show that the proposed design achieves an effective number of bits (ENOB) of 4.66 bits. The total power consumption of the proposed architecture using power saving scheme reduces at least by a factor of 2.5 in all the corners when compared to the existing standard cell based Flash ADC without power saving scheme.

BCS: Bidirectional Cross-Interface Scheduling for Sustainable End-to-End Data Delivery in IoT

In this era of Internet of Things (IoT), a variety of battery-powered devices communicate with each other or some remote gateways via wireless multihop communications. Although Wi-Fi has been shown to be of great benefit to a wide range of IoT applications due to its high data rate, high reliability, and native IP compatibility, it is inherently energy-hungry and potentially suffers from a dilemma: more (less) frequent use of Wi-Fi results in shorter (longer) delay but higher (lower) energy consumption. This dilemma becomes the major obstacle in the use of Wi-Fi in long-term but delay-bounded IoT applications. To address this, we propose a bidirectional cross-interface scheduling (BCS) scheme, which leverages the widely used low-power ZigBee to collaborate with the high data rate and reliable Wi-Fi for sustainable and reliable end-to-end (E2E) data delivery in IoT. The objective is to maximize network lifetime while satisfying certain required E2E delay bound. Extensive simulations and testbed experiments have been conducted. The results show that the network lifetime of BCS is 33.4% and 346.9% longer than those of a state-of-the-art scheme and the IEEE 802.11's standard power-saving scheme with the default settings, respectively.

CSI Based Multiple Relay Selection and Transmit Power Saving Scheme for Underlay CRNs Using FRBS and Swarm Intelligence

In this article, a multiple relay selection (MRS) scheme for signal-to-noise ratio (SNR) enhancement is proposed for underlay relay-assisted cognitive radio networks (RCRNs). A secondary source-destination pair experiencing deep fading on direct path is assisted by amplify-and-forward (AF) relays in an underlay mode. In this energy-constrained scenario, the aim is to maximize the secondary network's end-to-end SNR through an intelligent power-saving method incorporated with MRS. In contrast to the prior relay selection (RS) schemes, the relay-selection factor is the difference of SNR of the source-relay link and corresponding relay-destination link for each relay along with its corresponding interference channel coefficient. The difference factor aims to achieve the SNR upper bound while performing minimum power amplification, eventually resulting in interference mitigation as well. The proposed algorithm has been implemented using Fuzzy Rule Based System (FRBS), Artificial Bee Colony (ABC) and Particle Swarm Optimization (PSO) and their performance has been compared through simulations.

Remote-Controlled Fully Implantable Neural Stimulator for Freely Moving Small Animal

The application of a neural stimulator to small animals is highly desired for the investigation of electrophysiological studies and development of neuroprosthetic devices. For this purpose, it is essential for the device to be implemented with the capabilities of full implantation and wireless control. Here, we present a fully implantable stimulator with remote controllability, compact size, and minimal power consumption. Our stimulator consists of modular units of (1) a surface-type cortical array for inducing directional change of a rat, (2) a depth-type array for providing rewards, and (3) a package for accommodating the stimulating electronics, a battery and ZigBee telemetry, all of which are assembled after independent fabrication and implantation using customized flat cables and connectors. All three modules were packaged using liquid crystal polymer (LCP) to avoid any chemical reaction after implantation. After bench-top evaluation of device functionality, the stimulator was implanted into rats to train the animals to turn to the left (or right) following a directional cue applied to the barrel cortex. Functionality of the device was also demonstrated in a three-dimensional (3D) maze structure, by guiding the rats to better navigate in the maze. The movement of the rat could be wirelessly controlled by a combination of artificial sensation evoked by the surface electrode array and reward stimulation. We could induce rats to turn left or right in free space and help their navigation through the maze. The polymeric packaging and modular design could encapsulate the devices with strict size limitations, which made it possible to fully implant the device into rats. Power consumption was minimized by a dual-mode power-saving scheme with duty cycling. The present study demonstrated feasibility of the proposed neural stimulator to be applied to neuroprosthesis research.

Power Saving Scheme by Distinguishing Traffic Patterns for Event-Driven IoT Applications

Power Saving Scheme by Distinguishing Traffic Patterns for Event-Driven IoT Applications

User-Satisfaction-Aware Power Management in Mobile Devices Based on Perceptual Computing

Present day portable devices such as laptops, smartphones, etc., offer their users fastest processors, advanced operating systems, and numerous applications. However, a large section of the users are critical to the available battery capacity and its lifetime. This is because performance of the battery and its lifetime as perceived by the users are quite subjective in nature. It depends directly on user satisfactions, which are usually expressed in terms of words. So, in this paper, we propose a user-satisfaction-aware energy management approach, called “perceptual computer power management approach (Per-C PMA),” based on the technique of perceptual computing. At the heart of our technique is the perceptual computer that processes the linguistic input of the users to aid in the selection of a suitable processor frequency, which plays a significant role in the overall energy consumption of the systems. The Per-C PMA minimizes the energy consumption, while still keeping the user satisfied with the perceived system performance. The Per-C PMA achieves 1) reductions of 42.26% and 10.84% in power consumption, and 2) improvements in the overall satisfaction ratings of 16% and 10%, when compared to other existing power-saving schemes such as ON-DEMAND and human and application-driven frequency scaling for processor power efficiency, respectively. Per-C PMA is the first such application of Per-C on any hardware platform. It is implemented as Ubuntu scripts for end users and can be downloaded from: http://sau.ac.in/∼cilab/ . We have also provided the MATLAB files so that interested researchers can use it in their research. For the ease of the users, the Ubuntu scripts and the MATLAB codes are given in the graphical user interface mode; a demo video on how to use the software is also provided on the webpage.

Power saving with CoMP transmission for densely deployed small cell networks

Small cell base stations (SBSs) are being developed as a way of expanding the coverage of cellular networks. However, the power consumption of small cell networks has become an acute problem. To mitigate this problem, we propose a new power-saving scheme based on coordinate multi-point (CoMP) transmission for densely deployed small cell networks. This scheme turns off lightly loaded SBSs and switches their users to the cooperative clusters formed by their neighbor SBSs. The cooperative clusters adopt the virtual multiple-input multiple-output (MIMO) technology to serve the users in the switched-off SBSs. To achieve high power-efficiency, we first model the power consumption of all the SBSs by considering the quality of service of users in the switched-off SBSs and then provide in-depth proofs and analysis according to characteristics of small cell networks. Our extensive simulation results show that the proposed algorithm improves system power-saving efficiency significantly.

Locally Repairable Regenerating Codes: Node Unavailability and the Insufficiency of Stationary Local Repair

Recent works by Ahmad et al. and by Hollmann studied the concept of “locally repairable regenerating codes (LRRCs)” that successfully combines the functional repair and partial information exchange of regenerating codes (RCs) with the much-desired local repairability feature of locally repairable codes (LRCs). One important issue that needs to be addressed by any local repair schemes (including both LRCs and LRRCs) is that sometimes designated helper nodes may be temporarily unavailable, the result of various reasons that include multiple failures, degraded reads, or power-saving strategies to name a few. Under the setting of LRRCs with temporary node unavailability, this paper studies the impact of different helper selection methods. It proves that with node unavailability, all existing methods of helper selection, including those used in RCs and LRCs, can be insufficient in terms of achieving the optimal repair-bandwidth. For some scenarios, it is necessary to combine LRRCs with a new class of helper selection methods, termed dynamic helper selection , to achieve optimal repair-bandwidth. This paper also compares the performance of different classes of helper selection methods and answers the following fundamental question: is one method of helper selection intrinsically better than the other? for various scenarios.

A Novel Power Saving Scheme for Base Stations in 5G Network

A Novel Power Saving Scheme for Base Stations in 5G Network

Efficient Searching with a TCAM-based Parallel Architecture

Ternary Content-Addressable Memory (TCAM) is a popular hardware device for fast IP address lookup. High link transmission speed of Internet backbone demands more powerful IP address lookup engine. Restricted by the memory access speed, the lookup engine for next-generation routers demands exploiting parallelism among multiple TCAM chips. How to design an efficient engine with high IP lookup speed and less update time while keeping low power consumption is a great challenge in building the next-generation routers. At present, no parallel schemes can make full use of TCAM chips’ capability. In this paper, we propose a fast lookup, efficient update and power-saving scheme which can basically make full use of TCAM chips’ capability. With N parallel TCAM chips, our proposed scheme can achieve a worst-case speedup factor of (N-1)*90% in cache-update state, and a worst-case speedup factor of N*90% in normal work state. Compared with previous works, our scheme can apparently improve IP lookup performance and update efficiency while keeps low power consumption.

표준기상데이터 작성을 위한 국내 기후특성을 고려한 일사량 예측 모델 적합성 평가

As the energy saving issues become one of the important global agenda, the building simulation method is generally used to predict the inside energy usage to establish the power-saving strategies. To foretell an accurate energy usage of a building, proper and typical weather data are needed. For this reason, typical weather data are fundamental in building energy simulations and among the meteorological factors, the solar irradiation is the most important element. Therefore, preparing solar irradiation is a basic factor. However, there are few places where the horizontal solar radiation in domestic weather stations can be measured, so the prediction of the solar radiation is needed to arrive at typical weather data. In this paper, four solar radiation prediction models were analyzed in terms of their applicability for domestic weather conditions. A total of 12 regions were analyzed to compare the differences of solar irradiation between measurements and the prediction results. The applicability of the solar irradiation prediction model for a certain region was determined by the comparisons. The results were that the Zhang and Huang model showed the highest accuracy (Rad 0.87~0.80) in most of the analyzed regions. The Kasten model which utilizes a simple regression equation exhibited the second-highest accuracy. The Angstrom-Prescott model is easily used, also by employing a plain regression equation Lastly, the Winslow model which is known for predicting global horizontal solar irradiation at any climate regions uses a daily integration equation and showed a low accuracy regarding the domestic climate conditions in Korea.

Tradeoff design of radio resource scheduling for power and spectrum utilizations in LTE uplink systems

Power and spectrum efficiency have been the concerns for the customers in Long term evolution (LTE) uplink system. On one hand, due to the limited spectrum, it is difficult to provide a high quality of service (QoS) to the user equipment (UE) in a heavy traffic load. On the other hand, people have been paying more attention to the energy efficiency because of the battery constraint and the decreasing size of the mobile devices. Even though the issues mentioned above have been addressed in the literature, the study about tradeoff design of both two issues is sparse. The rationale for the tradeoff is that due to the fast changeable channel conditions and unpredictable data requests from UEs, adopting the unique resource allocation scheme, either power-saving (PS) or spectrum-saving (SS) scheme, is not flexible. Therefore, this paper proposes a tradeoff method to dynamically choose either PS or SS scheme according to the changeable UE's request and channel conditions. In the proposed system, multi-class UEs are considered. The performance of the PS-only scheme, SS-only scheme and the proposed hybrid scheme (H-PSSS) are analyzed and compared. Results show that the proposed hybrid scheme achieves the desired performance.

An Efficient Tree-Based Power Saving Scheme for Wireless Sensor Networks With Mobile Sink

Wireless sensor networks (WSNs) with mobile sink are expected to increase the flexibility for gathering information in large-scale sensing and detecting environments. Energy saving becomes one of the most important features of the sensor nodes to extend their lifetime in such networks. A novel tree-based power saving scheme is proposed in this paper to reduce the energy consumption in WSNs with mobile sink. We adopt a dynamic sorting algorithm to create a tree-cluster routing structure for the sensor nodes. The main goal of this scheme is to reduce the data transmission distances of the sensor nodes by employing the tree structure and multi-hop concepts. Based on the location of mobile sink, the distances between the sensor nodes, and the residual energy of each sensor node, the proposed scheme makes an efficient decision for creating the routing structure. The energy consumption is reduced and the lifetime is extended for the sensor nodes by balancing the network load. Simulation results demonstrate the superior performance of our proposed scheme and its ability to strike the appropriate performance in the energy consumption, network lifetime, throughput, and transmission overhead. In addition, suitable delay time and number of retransmission messages can be achieved for the WSNs with mobile sink.