An Evaluation of Smartphone Resources Used by Web Advertisements

With the rapid advancement of mobile devices, people have become more attached to them than ever. This rapid growth combined with millions of applications (apps) make smartphones a favourite means of communication among users. In general, the available contents on smartphones, apps and the web, come into two versions: (i) free contents that are monetized via advertisements (ads), and (ii) paid ones that are monetized by user subscription fees. However, the resources (energy, bandwidth, processing power) on-board are limited, and the existence of ads in either websites or free apps can adversely impact these resources. These issues brought the need for good understanding of the mobile advertising eco-system and how such limited resources can be efficiently used. This thesis focuses on mobile web browsing. Surfing web-pages on smatphones is one of the most commonly used task among smartphone users. However, web-page complexity is increasing, especially when designed for desktop computers. On one hand, the existence of ads in web-pages is essential for publishers' monetization strategy. On the other hand, their existence in webpages leads to even higher complexity of the webpages. This complexity in the smartphone environment, where the battery and bandwidth resources are limited, is reflected in longer loading time, more energy consumed, and more bytes transferred. With this view, quantifying the energy consumption due to web ads in smartphones is essential for publishers to optimize their webpages, and for system designers to develop an energy-aware applications (browsers) and protocols. Apart from their energy impact, ads consume network bandwidth as well. Therefore, quantifying the bandwidth consumption due to downloading web ads is crucial to creating more energy and bandwidth aware applications. This thesis first classifies web content into: (i) core information, and (ii) forced ``unwanted" information, namely ads. Then, describes an approach that enables the separation of web content in a number of a websites. Having done so, the energy cost due to downloading, rendering, and displaying web ads over Wi-Fi and 3G networks is evaluated. That is, how much energy web ads contribute to the total consumed energy when a user accesses the web. Furthermore, the bandwidth consumed by web ads in a number of well-known websites is also evaluated. Motivated by our findings about ads' impact on the energy and bandwidth, the thesis proposes and implements a novel web-browsing technique that adapts the webpages delivered to smartphones, based on a smartphone's current battery level and the network type. Webpages are adapted by controlling the amount of ads to be displayed. Validation tests confirm that the system, in some cases, can extend smartphone battery life by up to ~ 30\% and save wireless bandwidth up to ~ 44\%

Design and implementation of a traffic control framework in Firefox OS

Today's smartphones include a rich feature-set as well as various wireless interfaces that provide extra services rather than just voice communication or messaging, as it occurred with traditional mobile phones. Additionally, the widespread use of mobile devices using Third Generation (3G) and Long Term Evolution (LTE) networks has led to the development of various applications (apps) that take advantage of the always-on Internet connectivity provided by these networks (e.g. instant messaging and social network services). Unlike traditional Internet apps (e.g. web surfing and file transfer), the emerging apps that rely on always-on connectivity are often constantly running in the background to receive messages and status updates. This behavior causes that apps continuously generate short app signaling messages such as keep-alive and ping requests to maintain the always-on connectivity. Although the traffic volume of keep-alive messages is not large, frequent short messages can incur a large amount of related signaling traffic in the mobile network. In 3G or LTE networks, the User Equipment (UE) and the Radio Access Network (RAN) keep the Radio Resource Control (RRC) states. The UE stays in Connected mode when it transmits or receives data during active periods and stays in Idle mode during inactive periods. To send even a small data packet, the UE changes the state to the Connected mode prior to transmission. This radio state change generates a lot of network signaling messages, resulting in a rapid increase in traffic loading. Large amounts of network signaling traffic leads to two major problems: rapid drainage of the mobile device's battery and a signaling traffic surge in the mobile network. Since the air interface is a spare resource and the traffic for mobile end devices will grow enormously, it is important that the wireless resources are used in the most efficient way. However, this is not true for current networks as there is not alignment between devices, apps and the network.This document proposes a traffic control framework which acts as an interface between the apps and the network and allows the network operator to aggregate packets prior to transmission. The aggregated packets are sent out at once after a configurable amount of time which means for instance that resources on the wireless link have to be reserved only once for a number of app signaling packets and not for each packet separately. By this the packet transmission will be bursty which will improve network efficiency as the amount of signaling messages is minimized. In addition, battery runtime is improved as lower signaling overhead will reduce the activity time and energy consumption within devices.Hoy en día los smartphones incorporan un amplio conjunto de utilidades, así como varias interfaces inalámbricas que proporcionan servicios adicionales a los ofrecidos por los teléfonos móviles convencionales. Por otra parte, el uso generalizado de las redes 3G y LTE ha originado el desarrollo de numerosas aplicaciones que aprovechan las ventajas que ofrecen dichas redes, un ejemplo son las aplicaciones de redes sociales. Estas aplicaciones, a diferencia de otras como la navegación web o la descarga de archivos, están constantemente ejecutándose en segundo plano y recibiendo notificaciones de actualización de estado. Este comportamiento propicia el intercambio de pequeños mensajes de señalización para mantener la conexión, tales como mensajes "keep alive" o "ping requests". A pesar de que el volumen de estos mensajes no es elevado, su constante intercambio puede ocasionar una gran cantidad de tráfico de señalización en la red. En las redes 3G o LTE, el equipo de usuario (UE) y la red de acceso radio terrestre (RAN) mantienen los estados RRC. El equipo de usuario permanece en el estado activo cuando transmite o recibe datos y retorna al estado de reposo durante los periodos inactivos. El envío de un pequeño paquete de datos supone la transición desde el estado de reposo al estado activo. Este comportamiento genera muchos mensajes de señalización e implica un rápido incremento en el tráfico de la red. Este incremento del tráfico de señalización ocasiona dos grandes problemas: la sobrecarga de la red y un impacto negativo en el consumo de batería de los dispositivos móviles. Es de vital importancia que se haga un uso eficiente de los recursos de red, ya que el aire, en este caso el canal de comunicación, es un medio compartido. Además, se espera que el tráfico generado por los dispositivos móviles crezca enormemente en los próximos años. Las redes móviles actuales no son utilizadas de un modo eficiente debido a la falta de interacción entre la red, los dispositivos móviles y las aplicaciones. Este documento presenta una plataforma de control de tr a co que actúa como interfaz entre las aplicaciones y la red, permitiendo al operador de red agregar los paquetes antes de su transmisión. Esto permite, por ejemplo, que los recursos de red sean reservados s olo una vez para la ráfaga de paquetes y no para cada paquete individualmente, lo cual minimiza la cantidad de mensajes de señalización. Esta propuesta no sólo ayuda a mejorar la eficiencia de la red, sino que además optimiza el uso de la batería, ya que una disminución del tráfico de señalización provoca una reducción del tiempo de actividad y consumo de energía de los dispositivos móviles.Ingeniería Telemátic

Mobility: a double-edged sword for HSPA networks

This paper presents an empirical study on the performance of mobile High Speed Packet Access (HSPA, a 3.5G cellular standard) networks in Hong Kong via extensive field tests. Our study, from the viewpoint of end users, covers virtually all possible mobile scenarios in urban areas, including subways, trains, off-shore ferries and city buses. We have confirmed that mobility has largely negative impacts on the performance of HSPA networks, as fast-changing wireless environment causes serious service deterioration or even interruption. Meanwhile our field experiment results have shown unexpected new findings and thereby exposed new features of the mobile HSPA networks, which contradict commonly held views. We surprisingly find out that mobility can improve fairness of bandwidth sharing among users and traffic flows. Also the triggering and final results of handoffs in mobile HSPA networks are unpredictable and often inappropriate, thus calling for fast reacting fallover mechanisms. We have conducted in-depth research to furnish detailed analysis and explanations to what we have observed. We conclude that mobility is a double-edged sword for HSPA networks. To the best of our knowledge, this is the first public report on a large scale empirical study on the performance of commercial mobile HSPA networks