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Wireless sensor network has been an area of interest among researchers. Designing a wireless sensor network involves multiple issues such as size and processing capacity of the sensors, number of the cluster heads, number of the base stations, routing protocols, battery of the nodes, layout of the system, etc. Battery is a critical factor, since sensor networks do not involve maintenance as they are situated in remote places. Hence the available battery must be utilized effectively to increase the efficiency. In our study we address issues associated with battery such that to increase the lifetime of the system. Existing standards for the sensors are implemented with each node having equal battery level `B' referred to as `Uniform system' in our study. Thus total amount of battery consumed by N nodes is `N * B'. In our approach we study the distribution of this `N * B' battery in non-uniform manner, referred as `Non-uniform system', such that each node would be allocated with different battery level depending upon its position and amount of information it receives and transmits. Initially we commence with the observation of the behavior of this approach on a chain of nodes. These nodes generate information at constant rate and transmit per cycle. We observed that there is a huge amount of increase in the lifetime as compared to lifetime of the uniform system. We step further in our experimentation by restricting the amount of battery each node can have and then quantizing it. Results indicate that only 3 levels of batteries instead of N, give us significant increase in the lifetime. These results validate our approach for practical implementation. We progressed by observing success of our approach on random topology where nodes are laid randomly in the area of experimentation. Approximately same increase in the lifetime as achieved initially without restricting battery levels can be achieved. Simulation results show that non-uniform system performs much better than uniform system. This approach of non uniform battery levels can be implemented in sensor networks such that system lives longer giving more throughput and thus increasing efficiency.

Machine-to-Machine Communication (M2M) is the communications between wireless devices without human interventions. As a fundamental enabler of Internet of Things, M2M is growing fast and implemented in many areas. The number of M2M devices is expected to be extremely large in the future. In most cases they are battery driven and positioned in broad areas so that it would be costly to frequently replace or charge their batteries. To save the cost of maintaining M2M systems in the long term, energy consumption needs to be minimized so that battery lives of M2M devices can be maximized, which motivates the design of a lowpower MAC protocol in this thesis. The related works have indicated that idle listening and collisions are the main sources of power waste. In the proposed low-power MAC protocol design, various methods that would help preserving energy are considered. We first analyze the performance of three conventional protocols, TDMA, CSMA, and reservation-based protocol. The packet delay, energy consumption, and system throughput performances of these protocols are evaluated with both theoretical analysis and numerical simulations. Our results show that CSMA has better packet delay and throughput performances while static and dynamic TDMAs are more energy efficient. Furthermore, we design a hybrid energy-efficient MAC protocol for M2M communications. This solution not only improves existing protocols, but also takes the advantage of clustering in cellular networks to save energy. We show by simulation results that the proposed MAC protocol outperforms others in energy saving, without sacrificing much on delay or throughput. This is because with clustering, transmission power of remote nodes can be greatly reduced after they become members of clusters. With the proposed MAC protocol, the lifetimes of both individual nodes and the whole M2M network are significantly extended.

Didelis energijos suvartojimas yra labai svarbi detalė sistemoms, naudojančioms baterijas: nešiojami kompiuteriai, delninukai, mobilieji telefonai ir t.t. Pradėjus naudoti objektiškai orientuotas sistemas, buvo susirūpinta energijos taupymu. Todėl išsiaiškinus, kokią įtaką daro objektiškai orientuotos sistemos baterijos gyvavimo ciklui, galima būtų padėti programuotojams kurti tokias programas, kurios vartoja mažiau energijos. Darbe sukuriau programą, kuri sodina bateriją. Programoje naudojamos išretintos matricos. Pasinaudojus išretintų matricų saugojimo pagal eilutes metodu, kuris leidžia sumažinti matricos formatą, išmetant nulinius elementus, galime stebėti, kaip keičiasi sistemos resursų sunaudojimas, keičiant pradinėje matricoje nulinių elementų skaičių. Atlikę daugybą, galime įvertitni, kiek energijos suvartojo optimizuotas programos kodas ir neoptimizuotas. Atlikus eksperimentą, rezultatai parodė, jog optimizuotas kodas žymiai mažiau nusodina bateriją nei neoptimizuotas. To pasekoje galime daryti išvada, kad sistemos, kuriose yra optimizuotos programos, veiks ilgiau nei sistemos su neoptimizuotu kodu. / Low power consumption is a major constraint for battery-powered system like computer notebook or pocket PC, mobile phone. In the past, specialists usually designed both specific optimized equipments and codes to relief this concern. Doing like this could work for quite a long time, however, in this era, there is another significant restraint, the time to market. To be able to serve along the power constraint while can launch products in shorter production period, objectoriented programming (OOP) has stepped in to this field. In work we create program, whose multiply sparse matrix. Multiplication are two types: one we use standart matrix multiplication, other use compresed matrix storage by rows multiplication. When execute program, we can track, how battery power are consumpt. When we use compresed matrix storage by rows multiplication, we eliminate zero elements and multiplication execute faster, then standart matrix multiplication. So baterry power comsumption are lower. If your system are very important battery life time, then you must use optimized programm code. Optimized programm code use less battery power, then not optimized. Then your system can work much longer.

Today, it is not unusual that smartphone devices can’t survive even one day of regular use until the battery needs to be recharged. The batteries are drained while using power hungry applications made by developers who haven’t taken their application’s energy impact into consideration. In this thesis we study network transmissions as made by a mobile application, and the impact these have on the battery life. The application was developed with the local rescue and emergency service as a hypothetical target group. We test how the mobile network technologies 3G and WiFi together with the device’s current signal strength and battery level affect the energy usage of the battery when uploading data to a server. We develop an adaptation mechanism on application level which uses a mathematical model for calculating a suitable adaptation of scheduling of network interactions. The adaptation mechanism makes use of burst buffering of packets, and adjusts for 3G tail times as well as for different priorities of incoming requests. Custom packet scheduling profiles are made to make consistent measurements, and with this implementation we are able to reduce the amount of energy consumed using 3G and WiFi with 67 % and 39 % respectively during tests.

Abstract Peer-to-Peer (P2P) networking changes the way of people utilizing Internet, for example, sharing and consuming digital content, from the ground up. It continues to show its power and strength when it is combined with other emerging technologies, such as Web Services. This thesis contributes to the research and development of P2P networks from four aspects. Firstly, a P2P and Web Services converged multiple-tier system architecture is proposed. The architecture proposed enables providing Web Services in the context of heterogeneous access networks in an efficient way by utilizing P2P paradigm. A lightweight middleware architecture is introduced to fit the diversified mobile terminals. A theoretical analysis is given to provide a comparative study with the conventional centralized architecture. Secondly, a General Truncated Pyramid Peer-to-Peer (GTPP) architecture is presented to analyze the performance of hierarchical architecture compared with flat architecture. The motivation behind the GTPP architecture is to see whether an added tier can bring with it added value and functionality. A detailed mathematical analysis is provided which takes into consideration various performance metrics, including the lookup hopcount, lookup latency, maintenance traffic from a single peer point of view, and maintenance traffic from the whole system point of view. Furthermore, simulation results with respect to the lookup hopcount are also provided. Through mathematical analysis and simulation results, an optimal value regarding the number of tiers of the GTPP architecture is found, showing that 2~3 tiers are appropriate for most of situations. A specialized model is also proposed to improve the performance of hierarchical architecture. Thirdly, the performance evaluation of a communication-oriented Kademlia-based P2P system is provided in detail. NetHawk EAST-based simulation models and a prototype are both utilized to evaluate the performance. Simulation results from NetHawk EAST-based simulation models demonstrate the optimal design choices regarding the resource lookup parallelism degree and resource replication degree, and show the unnecessary existence of the messages used to detect the liveness of peers in a DHT overlay. Measurements from the prototype show the feasibility of mobile nodes acting as fully fledged overlay nodes from three different perspectives, namely CPU processing load, network traffic load, and battery consumption. The optimal size of packets which consumes battery in the most efficient way is also found through battery consumption measurements. Fourthly, the effects of different churn models on the performance of structured P2P networks are analyzed. Specifically, three typical churn models are analyzed to provide a comparative result. The simulation results show that the difference among the effects of different churn models on the performance of structured P2P networks is quantitative rather than qualitative. This provides some guidance for the selection of different churn models for the contemporary researchers.

The climate change has been an ongoing debate throughout the years. There are already some devices that monitor the changing of the climate, CanSat is a good example. The main goal of this project is to create a CanSat prototype and analyse the power used by it. The focus is on several factors such as the use of power with and without an upload program, the use of power when the sensors are switched on/off and the duration of the battery using the prototype. Some parts of the analysis have been done theoretically and practical. The project has been conducted with the aid of Arduino, an ammeter, and a voltmeter. The results show that the prototype would not spare much power if the sensors are switched off and on, this because not all the sensors have implemented the “sleep mode”. The difference between sleep mode and the normal functionality is equal to 0.026𝑊. Moreover, the difference in power when there is an upload program and when there is not an upload program is equal to 0.057𝑊. The duration of battery in the prototype is equal to 1 hour and 45 minutes according to the theoretical part, while the practical part showed a duration of 1 hour and 11 minutes. Moreover, the results show also that the prototype send the wrong values for some of the sensors when the battery have a low value. It was estimated a value of 7V of battery left to guarantee credible measurements. From the result it is possible to deduce that the decrease of power used from the CanSat prototype can be improved by finding sensors that have implemented the sleep mode, by having a small code and by having an electric platform that consume less power than Arduino. Keywords: CanSat, Power consumption, Battery life, Arduino.

No description available.

The batteries used in plug-in hybrid electric vehicles (PHEVs) need to overcome significant technical challenges in order for PHEVs to become economically viable and have a large market penetration. The internship at Argonne National Laboratory (ANL) involved two experiments which looked at a vehicle systems approach to analyze two such technical challenges: Battery life and low battery power at cold (-7 ⁰C) temperature. The first experiment, concerning battery life and its impact on gasoline savings due to a PHEV, evaluates different vehicle control strategies over a pre-defined vehicle drive cycle, in order to identify the control strategy which yields the maximum dollar savings (operating cost) over the life of the vehicle, when compared to a charge sustaining hybrid. Battery life degradation over the life of the vehicle, and fuel economy savings on every trip (daily) are taken into account when calculating the net present value of the gasoline dollars saved. The second experiment evaluates the impact of different vehicle control strategies in heating up the PHEV battery (due to internal ohmic losses) for cold ambient conditions. The impact of low battery power (available to the vehicle powertrain) due to low battery and ambient temperatures has been well documented in literature. The trade-off between the benefits of heating up the battery versus heating up the internal combustion engine are evaluated, using different control strategies, and the control strategy, which provided optimum temperature rise of each component, is identified.

This thesis proposes an implementation of battery-powered, time-synchronized wireless nodes that can be deployed in a wireless network topology. Wireless sensor networks are used in a wide variety of scenarios where emphasis is placed on the wireless nodes’ battery life. The main area of focus in this thesis is to examine how wireless nodes can save battery power by utilizing a deep sleep mode and wake up simultaneously using time synchronization to carry out their data communication. This was achieved by deploying five time-synchronized, battery-powered nodes in a wireless network topology. The difference in battery current draw between continuously running nodes and sleep-enabled nodes were measured, as well as the time duration needed by the nodes to successfully send their payloads and route other nodes’ data. The nodes needed between 1502 ms and 3273 ms on average to carry out their data communication, depending on where they were located in the network topology. Measurements show that sleep-enabled nodes on average draw substantially less current than continuously running nodes during a complete data communication cycle. When sleep-enabled nodes were powered by two AA batteries, an increase in battery life of up to 1800% was observed.