The advancement and popularity of smartphones have made it an essential and all-purpose device. But lack of advancement in battery technology has held back its optimum potential. Therefore, considering its scarcity, optimal use and efficient management of energy are crucial in a smartphone. For that, a fair understanding of a smartphone’s energy consumption factors is necessary for both users and device manufacturers, along with other stakeholders in the smartphone ecosystem. It is important to assess how much of the device’s energy is consumed by which components and under what circumstances. This paper provides a generalized, but detailed analysis of the power consumption causes (internal and external) of a smartphone and also offers suggestive measures to minimize the consumption for each factor. The main contribution of this paper is four comprehensive literature reviews on: 1) smartphone’s power consumption assessment and estimation (including power consumption analysis and modelling); 2) power consumption management for smartphones (including energy-saving methods and techniques); 3) state-of-the-art of the research and commercial developments of smartphone batteries (including alternative power sources); and 4) mitigating the hazardous issues of smartphones’ batteries (with a details explanation of the issues). The research works are further subcategorized based on different research and solution approaches. A good number of recent empirical research works are considered for this comprehensive review, and each of them is succinctly analysed and discussed.

/pdf/power-consumption-analysis-measurement-management-and-issues-2oowtxtoal.pdf

Power Consumption Analysis, Measurement, Management, and Issues: A State-of-the-Art Review of Smartphone Battery and Energy Usage

https://hal-amu.archives-ouvertes.fr/hal-02740661/document

Power profiling and monitoring in embedded systems: A comparative study and a novel methodology based on NARX neural networks

Les systemes-sur-puce (Systems on Chip, SoC) sont de plus en plus embarques dans des systemes a risque comme les systemes aeronautiques et les equipements de production d’energie. Cette evolution technologique permet un gain de temps et de performance, mais presente des limites en termes de fiabilite et de securite. Ainsi, le developpement d’outils de surveillance et de diagnostic des systemes electroniques embarques, en particuliers les SoC, est devenu l’un des verrous scientifiques a lever pour assurer une large utilisation de ces systemes dans les equipements a risque en toute securite. Ce travail de these s’inscrit dans ce contexte, et a pour objectif le developpement d’une approche de detection et identification des derives des performances des SoC embarques. L’approche proposee est basee sur un modele incremental, construit a partir de modules reutilisables et echangeables pour correspondre a la large gamme de SoC existants sur le marche. Le modele est ensuite utilise pour estimer un ensemble de caracteristiques relatives a l’etat de fonctionnement du SoC. L’algorithme de diagnostic developpe dans ce travail consiste a generer des indices de derives par la comparaison en ligne des caracteristiques estimees a celles mesurees. L’evaluation des residus et la prise de decision sont realisees par des methodes statistiques appropriees a la nature de chaque indice de derive. L’approche developpee a ete validee experimentalement sur des SoC differents, ainsi que sur un demonstrateur developpe dans le cadre de ce travail. Les resultats experimentaux obtenus, montrent l’efficacite et la robustesse de l’approche developpee

https://tel.archives-ouvertes.fr/tel-02472080/document

Modélisation Incrémentale des Processeurs Embarqués pour l'Estimation des Caractéristiques et le Diagnostic

This paper presents merits and feasibility of a new DC/DC Buck converter architecture where parasitic inductance available in a USB cable is utilized for energy storage element in an example mobile battery charger application. In this proposed architecture, strategizing the cable as inductor and the converter's active devices at the cable's input side enables inductor heat spread along the cable that has a large surface area. It also allows board size reduction and removes battery charger heat from the load system, e.g. in smart phones, whose stringent thermal limit has been a serious constraint. Since the load and active circuits are on different sides of the cable, the Indirect Control method is proposed to regulate the actual output voltage without directly sensing it as in conventional converters. The Indirect Control is analytically analyzed and verified in simulations and experiments using a 10W smart-USB-cable charger prototype for Li-ion battery application. The converter is switched at 2 MHz for a target voltage conversion from 5V to 3.3V and achieves stable operation across a wide load range and load transients.

A smart-USB-cable buck converter with indirect control

Tracking food consumption in household and monitoring the usage of items in kitchen everyday is incredible. Manual intervention of this process consumes time and is annoying. This paper presents a smart container for monitoring and tracking the food items stored in household kitchen. The proposed solution serves to provide an automated response on the level of the items stored in the container and also generates an alert on its expiry. A prototype of the proposed method is developed and tested for level and expiry detection.

Food Consumption Monitoring and Tracking in Household Using Smart Container

Energy cost of crowd-sourced continuous sensing is reported to be quite high. As the number of on-board active sensors increases, complications arise due to inter-sensor interactions. The energy-cost of the Smartphones is primarily due to wireless communications (in various modes, such as, cellular radio, GPS, Wi-Fi direct, and Bluetooth) and environmental sensing using its embedded sensors in a wireless personal area network setting. The existing popular on-device-online energy-cost profilers for Android Smartphones, namely, Amobisense and PowerTutor, are energy-hungry. In this paper, we report an efficient on-demand-online profiler, called pProf, that learns from offline-precomputed model parameters to reduce the online profiling cost. We have tested our proposed technique in a customized test-bed setup comprising of the Android Smart-phones with embedded sensors that also communicate with the neighborhood sensors on smart-wearables and Sensorcon's Sensordrone platform. Our experimental measurement studies demonstrate that, compared to the popular profilers, such as Amobisense and PowerTutor, pProf consumes typically 10–15% lesser energy.

Utilization-based power consumption profiling in smartphones

This paper is about an innovative way to make the food containers smarter in a kitchen. Many times it has happened with us when we are in the supermarket and fail to recall what's missing in our kitchen which we need to buy? Or we are too lazy to check every jar in our kitchen to know this before we plan a visit to store. eZaar, a Grain Drain Monitor, empowers us to know the amount of food inside our kitchen containers on the fly. It makes us realize what we are eating, our carbohydrate, protein, fiber, sugar, salt, caffeine/tea intake. It also tracks and control your dietary habits and does food budget planning. It can be tied up with a grocery ordering mobile/web app and export the list of things to be ordered.

eZaar, the smart container

This paper is about an innovative and robust way to count human footsteps using accelerometer and proximity sensor (time of flight). The proximity compensation mechanism along with motion detection by accelerometer ensures to prevent false step detection. This solution can be used for smart shoe. Any shoe attached with this kind of solution will be smart enough to detect your step and calorie counts. When proper motion pattern is recognized by accelerometer, the time of flight sensor, on proximity to the ground, will detect a real step. Also this type of solution is going to help all those OEM/ODMs, who have introduced fitness bands for promotional purpose and providing rewards to the end user on daily/weekly step limit accomplishment.

Saurabh Rawat

Papers

Utilization-based power consumption profiling in smartphones

eZaar, the smart container

Human footstep detection using proximity compensation algorithm withaccelerometer and time of flight sensor