Toward Sustainable IoT Applications: Unique Challenges for Programming the Batteryless Edge

The advent of ultra-low-power computer systems has enabled intermittently powered, battery-free devices to operate using harvested ambient energy. We present a roadmap from today’s continuously powered Internet of Things devices to tomorrow’s battery-free devices that highlights challenges for those running intermittent programs.acceptedVersio

ETAP: Energy-Aware Timing Analysis of Intermittent Programs

Energy harvesting battery-free embedded devices rely only on ambient energy harvesting that enables stand-alone and sustainable IoT applications. These devices execute programs when the harvested ambient energy in their energy reservoir is sufficient to operate and stop execution abruptly (and start charging) otherwise. These intermittent programs have varying timing behavior under different energy conditions, hardware configurations, and program structures. This article presents Energy-aware Timing Analysis of intermittent Programs (ETAP), a probabilistic symbolic execution approach that analyzes the timing and energy behavior of intermittent programs at compile time. ETAP symbolically executes the given program while taking time and energy cost models for ambient energy and dynamic energy consumption into account. We evaluate ETAP by comparing the compile-time analysis results of our benchmark codes and real-world application with the results of their executions on real hardware. Our evaluation shows that ETAP’s prediction error rate is between 0.0076% and 10.8%, and it speeds up the timing analysis by at least two orders of magnitude compared to manual testing.acceptedVersio

A new operating system for embedded systems: eGIS

IEEE 15th Signal Processing and Communications Applications Conference -- JUN 11-13, 2007 -- Eskisehir, TURKEYWOS: 000252924600172Many embedded applications need a real-time and embedded operating system that provides an simple operation environment. Embedded operating systems that give service to embedded applications must be configurable and restructurable in contrast to general purpose operating systems. In this work, eGIS (Ege Gomulu Isletim Sistemi) which is a real-time, portable, configurable, object oriented and embedded operating system is implemented In this paper, the developed system is introduced and some experimental results are presented.IEE

External Gradient Time Synchronization in Wireless Sensor Networks

WOS: 000334672200011Synchronization to an external time source such as Coordinated Universal Time (UTC), i.e., external synchronization, while preserving tight synchronization among neighboring sensor nodes may be crucial for applications such as determining the speed of a moving object in wireless sensor networks. However, existing time synchronization protocols in the literature, which can be used for external synchronization, poorly synchronize neighboring nodes. On the other hand, the only protocol that aims at optimizing the synchronization error between neighboring nodes is lack of a mechanism which synchronizes sensor nodes to a reference node, and hence, it cannot provide external synchronization. Therefore, there is a lack in the literature of a time synchronization protocol, which can be used by applications demanding both external synchronization and tight synchronization among neighboring nodes. In this paper, we answer the question of whether it is possible for sensor nodes to synchronize to a reference node while they optimize the clock skew between their neighboring nodes at the same time. Within this context, we present a novel time synchronization protocol, namely External Gradient Time Synchronization Protocol (EGSync). In EGSync, each sensor node synchronizes to a reference node by using time information flooded by this node, as well as synchronizes to its neighboring nodes by employing the agreement algorithm. We implemented EGSync on the MICAz platform using TinyOS and evaluated it on a testbed setup including 20 sensor nodes. We present the experimental results on our testbed and the simulation results for networks with larger diameters and densities.Turkish Scientific and Technical Research Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [BAYG-2211]Kasim Sinan Yildirim acknowledges the Turkish Scientific and Technical Research Council (TUBITAK) for supporting this work through a domestic PhD scholarship program (BAYG-2211)

On Distributed Sensor Fusion in Batteryless Intermittent Networks

15th Annual International Conference on Distributed Computing in Sensor Systems (DCOSS) -- MAY 29-31, 2019 -- GREECEYildirim, Kasim Sinan/0000-0002-9528-6923WOS: 000502738800073Distributed and collaborative computation has never been considered before in networks of batteryless sensors. This can bring many advantages for applications (e.g. longer transmission ranges, lower network costs), however introducing new research challenges. in this paper, we focus on the well-known distributed sensor fusion but in an intermittently-powered batteryless sensor network. the goal is to estimate a parameter collaboratively by considering individual sensor measurements. We show that, even though the nodes stop operation with high probability due to random power failures and they neither communicate with their neighbors nor perform computation most of the time, the simplest implementation of the fully-distributed sensor fusion based on average consensus improves the overall estimation quality of the network considerably. in the light of this, we anticipate that if harvested energy is used efficiently so that nodes have more opportunity to receive and send packets, existing fully-distributed protocols can be implemented with tiny modifications in networks of batteryless sensors.IEEE Comp So