The Bits of Silence : Redundant Traffic in VoIP

Human conversation is characterized by brief pauses and so-called turn-taking behavior between the speakers. In the context of VoIP, this means that there are frequent periods where the microphone captures only background noise – or even silence whenever the microphone is muted. The bits transmitted from such silence periods introduce overhead in terms of data usage, energy consumption, and network infrastructure costs. In this paper, we contribute by shedding light on these costs for VoIP applications. We systematically measure the performance of six popular mobile VoIP applications with controlled human conversation and acoustic setup. Our analysis demonstrates that significant savings can indeed be achievable - with the best performing silence suppression technique being effective on 75% of silent pauses in the conversation in a quiet place. This results in 2-5 times data savings, and 50-90% lower energy consumption compared to the next better alternative. Even then, the effectiveness of silence suppression can be sensitive to the amount of background noise, underlying speech codec, and the device being used. The codec characteristics and performance do not depend on the network type. However, silence suppression makes VoIP traffic network friendly as much as VoLTE traffic. Our results provide new insights into VoIP performance and offer a motivation for further enhancements, such as performance-aware codec selection, that can significantly benefit a wide variety of voice assisted applications, as such intelligent home assistants and other speech codec enabled IoT devices.Peer reviewe

How do different devices impact users' web browsing experience?

The digital world presents many interfaces, among which the desktop and mobile device platforms are dominant. Grasping the differential user experience (UX) on these devices is a critical requirement for developing user focused interfaces that can deliver enhanced satisfaction. This study specifically focuses on the user's web browsing experience while using desktop and mobile. The thesis adopts quantitative methodology. This amalgamation presents a comprehensive understanding of the influence of device specific variables, such as loading speed, security concerns and interaction techniques, which are critically analyzed. Moreover, various UX facets including usability, user interface (UI) design, accessibility, content organization, and user satisfaction on both devices were also discussed. Substantial differences are observed in the UX delivered by desktop and mobile devices, dictated by inherent device attributes and user behaviors. Mobile UX is often associated with personal, context sensitive use, while desktop caters more effectively to intensive, extended sessions. A surprising revelation is the existing discrepancy between the increasing popularity of mobile devices and the persistent inability of many websites and applications to provide a satisfactory mobile UX. This issue primarily arises from the ineffective adaptation of desktop-focused designs to the mobile, underscoring the necessity for distinct, device specific strategies in UI development. By furnishing pragmatic strategies for designing efficient, user-friendly and inclusive digital interfaces for both devices; the thesis contributes significantly to the existing body of literature. An emphasis is placed on a device-neutral approach in UX design, taking into consideration the unique capabilities and constraints of each device, thereby enriching the expanding discourse on multiservice user experience. As well as this study contributes to digital marketing and targe­ted advertising perspe­ctives

How do different devices impact users' web browsing experience?

The digital world presents many interfaces, among which the desktop and mobile device platforms are dominant. Grasping the differential user experience (UX) on these devices is a critical requirement for developing user focused interfaces that can deliver enhanced satisfaction. This study specifically focuses on the user's web browsing experience while using desktop and mobile. The thesis adopts quantitative methodology. This amalgamation presents a comprehensive understanding of the influence of device specific variables, such as loading speed, security concerns and interaction techniques, which are critically analyzed. Moreover, various UX facets including usability, user interface (UI) design, accessibility, content organization, and user satisfaction on both devices were also discussed. Substantial differences are observed in the UX delivered by desktop and mobile devices, dictated by inherent device attributes and user behaviors. Mobile UX is often associated with personal, context sensitive use, while desktop caters more effectively to intensive, extended sessions. A surprising revelation is the existing discrepancy between the increasing popularity of mobile devices and the persistent inability of many websites and applications to provide a satisfactory mobile UX. This issue primarily arises from the ineffective adaptation of desktop-focused designs to the mobile, underscoring the necessity for distinct, device specific strategies in UI development. By furnishing pragmatic strategies for designing efficient, user-friendly and inclusive digital interfaces for both devices; the thesis contributes significantly to the existing body of literature. An emphasis is placed on a device-neutral approach in UX design, taking into consideration the unique capabilities and constraints of each device, thereby enriching the expanding discourse on multiservice user experience. As well as this study contributes to digital marketing and targe­ted advertising perspe­ctives

Understanding and Improving the Performance of Web Page Loads

The web is vital to our daily lives, yet web pages are often slow to load. The inefficiency and complexity of loading web pages can be attributed to the dependencies between resources within a web page, which also leads to underutilization of the CPU and network on client devices. My thesis research seeks solutions that enable better use of the client-side CPU and network during page loads. Such solutions can be categorized into three types of approaches: 1) leveraging a proxy to optimize web page loads, 2) modifying the end-to-end interaction between client browsers and web servers, and 3) rewriting web pages. Each approach offers various benefits and trade-offs. This dissertation explores three specific solutions. First, CASPR is a proxy-based solution that enables clients to offload JavaScript computations to proxies. CASPR loads web pages on behalf of clients and transforms every page into a version that is simpler for clients to process, leading to a 1.7s median improvement in web page rendering for popular CASPR web pages. Second, Vroom rethinks how page loads work; in order to minimize dependencies between resources, it enables web servers to provide resource hints to clients and ensures that resources are loaded with proper prioritization. As a result, Vroom halves the median load times for popular news and sports websites. Finally, I conducted a longitudinal study to understand how web pages have changed over time and how these changes have affected performance.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163157/1/vaspol_1.pd