Data Compression For Energy-Efficiency Web Access On Mobile Devices

Nowadays, wireless data connections (2G, 3G and WiFi) have been the main- stream technologies for accessing Internet on modern mobile devices. However, users aware that heavy use of data transmission for web access via wireless interfaces leads battery life drain badly. In order to extend battery life time and improve user experience, we present the solution for offering "energy-efficiency web access on mobile devices". A new compression strategy named selective-compression is introduced as an improvement of traditional HTTP compression in this thesis. The selective-compression strategy can properly handle binaries of web contents. And its mechanism relies on client/remote proxy pair structure. From analysis of the experiment results, we make conclusion that the selective-compression strategy can bring nice benefits for energy saving and delay deduction on mobile devices while accessing web pages that include massive binaries. Furthermore, we give the suggestion to web developers and web service providers about how to create energy-efficient web pages

On Providing Energy-efficient Data Transmission to Mobile Devices

The transformation from telephony to mobile Internet has fundamentally changed the way we interact with the world by delivering ubiquitous Internet access and reasonable cost of connectivity. The mobile networks and Internet services are supportive of each other and together drive a fast development of new services and the whole ecosystem. As a result, the number of mobile subscribers has skyrocketed to a magnitude of billions, and the volume of mobile traffic has boomed up to a scale no-one has seen before with exponential growth predictions. However, the opportunities and problems are both rising. Therefore, to enable sustainable growth of the mobile Internet and continued mobile service adaption, this thesis proposes solutions to ensure that the reduction of overall environmental presence and the level of QoE are mutually addressed by providing energy-efficient data transmission to mobile devices. It is important to understand the characteristics of power consumption of mobile data transmission to find opportunities to balance the energy consumption and the growth of mobile services and the data volumes. This research started with power consumption measurements of various radio interfaces and investigations of the trade-off between computation and communication of modern mobile devices. Power consumption models, state machines and the conditions for energy-efficient mobile data transmission were proposed to guide the development of energy-saving solutions. This research has then employed the defined guideline to optimise data transmission for energy-efficient mobile web access. Proxy-based solutions are presented in this thesis, utilising several strategies: bundling-enabled traffic shaping to optimise TCP behaviour over congested wireless links and keep the radio interface in low power consumption states as much as possible, offloading HTTP-object fetching to shorten the time of DNS lookups and web content downloading, and applying selective compression on HTTP payload to further reduce energy consumption of mobile data transmission. As a result, the solutions dramatically reduce the energy consumption of mobile web access and download time, yet maintain or even increase user experience

Security for Ubiquitous Internet-Connected Smart Objects

Ubiquitous computing, also called the Internet of Things (IoT), is rapidly transforming our lives and our society. The vision of an interconnected world where physical devices are seamlessly integrated into the Internet is becoming a reality. The emergence of low-cost microcontrollers, energy-efficient wireless communications, and embedded sensors and actuators has transformed everyday devices into connected smart objects that can understand and react to their environment. These devices include both resource-constrained battery-operated devices, such as body sensors, and more powerful Internet-connected appliances, such as televisions and cameras. However, the security mechanisms for smart objects are still not ready for wide-scale deployment. There is additionally a concern that the existing solutions are not sufficiently usable for adoption in everyday devices, which often have very limited user interfaces. In this dissertation, we develop new secure deployment and communication methods for connected smart objects that are simple, user-friendly, and also energy efficient. We take into account the entire lifecycle of a smart object. We first build a secure and energy-efficient communication model that uses a proxy to serve data on behalf of sleeping resource-constrained smart objects, thereby allowing them to appear as always-online web servers. Next, we demonstrate how these smart objects can leverage the existing mobile network infrastructure to securely authenticate and communicate with Internet services. Thereafter, we study the deployment challenges of electronic displays. We found that deploying large numbers of ubiquitous displays is cumbersome as they need to be correctly configured to access both the Internet and online servers, despite their minimal input capabilities. In our secure bootstrapping solution, the displays show a bar code which, when scanned by the user, enables automatic configuration of the wireless network along with the online management service and content to be shown. For effortless deployment, we build our solution on standard protocols without requiring changes to the network infrastructure. Finally, we develop a solution for securely pairing mobile devices. Instead of relying on inconvenient user-entered codes, our solution uses an out-of-band (OOB) channel which is secret from anyone that is not physically present. The protocol development was motivated by the invention of a new human source for fuzzy secrets: synchronized drawing with two fingers of the same hand on two touch screens or surfaces. We show the feasibility of each of our proposed solutions with prototype implementation. Where relevant, we also provide experimental results confirming that our solutions incur minimal memory and computational overhead, while also being energy efficient and easy to use. Lastly, we actively contribute the research results to relevant standards bodies

Doctor of Philosophy

dissertationThe computing landscape is undergoing a major change, primarily enabled by ubiquitous wireless networks and the rapid increase in the use of mobile devices which access a web-based information infrastructure. It is expected that most intensive computing may either happen in servers housed in large datacenters (warehouse- scale computers), e.g., cloud computing and other web services, or in many-core high-performance computing (HPC) platforms in scientific labs. It is clear that the primary challenge to scaling such computing systems into the exascale realm is the efficient supply of large amounts of data to hundreds or thousands of compute cores, i.e., building an efficient memory system. Main memory systems are at an inflection point, due to the convergence of several major application and technology trends. Examples include the increasing importance of energy consumption, reduced access stream locality, increasing failure rates, limited pin counts, increasing heterogeneity and complexity, and the diminished importance of cost-per-bit. In light of these trends, the memory system requires a major overhaul. The key to architecting the next generation of memory systems is a combination of the prudent incorporation of novel technologies, and a fundamental rethinking of certain conventional design decisions. In this dissertation, we study every major element of the memory system - the memory chip, the processor-memory channel, the memory access mechanism, and memory reliability, and identify the key bottlenecks to efficiency. Based on this, we propose a novel main memory system with the following innovative features: (i) overfetch-aware re-organized chips, (ii) low-cost silicon photonic memory channels, (iii) largely autonomous memory modules with a packet-based interface to the proces- sor, and (iv) a RAID-based reliability mechanism. Such a system is energy-efficient, high-performance, low-complexity, reliable, and cost-effective, making it ideally suited to meet the requirements of future large-scale computing systems

Recent advances in industrial wireless sensor networks towards efficient management in IoT

With the accelerated development of Internet-of- Things (IoT), wireless sensor networks (WSN) are gaining importance in the continued advancement of information and communication technologies, and have been connected and integrated with Internet in vast industrial applications. However, given the fact that most wireless sensor devices are resource constrained and operate on batteries, the communication overhead and power consumption are therefore important issues for wireless sensor networks design. In order to efficiently manage these wireless sensor devices in a unified manner, the industrial authorities should be able to provide a network infrastructure supporting various WSN applications and services that facilitate the management of sensor-equipped real-world entities. This paper presents an overview of industrial ecosystem, technical architecture, industrial device management standards and our latest research activity in developing a WSN management system. The key approach to enable efficient and reliable management of WSN within such an infrastructure is a cross layer design of lightweight and cloud-based RESTful web service