OF-ECF ::a new optimization of the objective function for parent selection in RPL

The RPL routing protocol is designed to respond to the requirements of a large range of Low-power and Lossy Networks (LLNs). RPL uses an objective function (OF) to build the route toward a destination based on routing metrics. Considering only a single metric, some network performances can be improved while others may be degraded. In this paper, we present a flexible Objective Function based on Expected Transmission Count (ETX), Consumed Energy and Forwarding Delay (OF-ECF) built on a combination of metrics using an additive method. The main goal of this proposed solution is to balance energy consumption and minimize the average delay. To improve the reliability of the network, a flexible routing scheme that provides the diversity of paths and a higher availability is presented. Simulations results show that the new objective function OF-ECF outperforms the OF-FUZZY, and the standards OF0 and MRHOF. In terms of network lifetime and reliability

Investigating Read/Write Aggregation to Exploit Power Reduction Opportunities Using Dual Supply Voltages

Power consumption plays an important role in computer system design today. On-chip memory structures such as multi-level cache make up a significant proportion of total power consumption of CPU or Application-Specific Integrated Circuit (AISC) chip, especially for memory-intensive application, such as floating-point computation and machine learning algorithm. Therefore, there is a clear motivation to reduce power consumption of these memory structures that are mostly consisting of Static Random-Access Memory (SRAM) blocks. In this defense, I will present the framework of a novel dual-supply-voltage scheme that uses separate voltage levels for memory read and write operations. By quantitatively analyzing the cache trace for SPEC2000, Parsec, and Cortexsuite benchmarks and comparing the Read/Write sequence characterization of different computing application types, I discover that memory-intensive applications have high potential to generate long consecutive Read/Write sequences, which can be leveraged by our proposed dual-supply framework. I then perform a limit study based on ideal Read/Write re-ordering to obtain the maximum possible power saving estimate. Finally, as a case study, I apply this framework to a custom machine learning ASIC accelerator design to showcase its viability

Trust-based energy efficient routing protocol for wireless sensor networks

Wireless Sensor Networks (WSNs) consist of a number of distributed sensor nodes that are connected within a specified area. Generally, WSN is used for monitoring purposes and can be applied in many fields including health, environmental and habitat monitoring, weather forecasting, home automation, and in the military. Similar, to traditional wired networks, WSNs require security measures to ensure a trustworthy environment for communication. However, due to deployment scenarios nodes are exposed to physical capture and inclusion of malicious node led to internal network attacks hence providing the reliable delivery of data and trustworthy communication environment is a real challenge. Also, malicious nodes intentionally dropping data packets, spreading false reporting, and degrading the network performance. Trust based security solutions are regarded as a significant measure to improve the sensor network security, integrity, and identification of malicious nodes. Another extremely important issue for WSNs is energy conversation and efficiency, as energy sources and battery capacity are often limited, meaning that the implementation of efficient, reliable data delivery is an equally important consideration that is made more challenging due to the unpredictable behaviour of sensor nodes. Thus, this research aims to develop a trust and energy efficient routing protocol that ensures a trustworthy environment for communication and reliable delivery of data. Firstly, a Belief based Trust Evaluation Scheme (BTES) is proposed that identifies malicious nodes and maintains a trustworthy environment among sensor nodes while reducing the impact of false reporting. Secondly, a State based Energy Calculation Scheme (SECS) is proposed which periodically evaluates node energy levels, leading to increased network lifetime. Finally, as an integrated outcome of these two schemes, a Trust and Energy Efficient Path Selection (TEEPS) protocol has been proposed. The proposed protocol is benchmarked with A Trust-based Neighbour selection system using activation function (AF-TNS), and with A Novel Trust of dynamic optimization (Trust-Doe). The experimental results show that the proposed protocol performs better as compared to existing schemes in terms of throughput (by 40.14%), packet delivery ratio (by 28.91%), and end-to-end delay (by 41.86%). In conclusion, the proposed routing protocol able to identify malicious nodes provides a trustworthy environment and improves network energy efficiency and lifetime