%0 Journal Article
%T Angry Apps: The Impact of Network Timer Selection on Power Consumption, Signalling Load, and Web QoE
%A Christian Schwartz
%A Tobias Ho£¿feld
%A Frank Lehrieder
%A Phuoc Tran-Gia
%J Journal of Computer Networks and Communications
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/176217
%X The popularity of smartphones and mobile applications has experienced a considerable growth during the recent years, and this growth is expected to continue in the future. Since smartphones have only very limited energy resources, battery efficiency is one of the determining factors for a good user experience. Therefore, some smartphones tear down connections to the mobile network soon after a completed data transmission to reduce the power consumption of their transmission unit. However, frequent connection reestablishments caused by apps which send or receive small amounts of data often lead to a heavy signalling load within the mobile network. One of the major contributions of this paper is the investigation of the resulting tradeoff between energy consumption at the smartphone and the generated signalling traffic in the mobile network. We explain that this tradeoff can be controlled by the connection release timeout and study the impact of this parameter for a number of popular apps that cover a wide range of traffic characteristics in terms of bandwidth requirements and resulting signalling traffic. Finally, we study the impact of the timer settings on Quality of Experience (QoE) for web traffic. This is an important aspect since connection establishments not only lead to signalling traffic but also increase the load time of web pages. 1. Introduction Together with the wide-spread usage of smartphones in today's UMTS networks, the popularity of smartphone apps has seen a tremendous growth during the last years [1]. The resulting traffic is expected to exceed half of the global mobile data traffic in the next years [2]. One of the major reasons for this phenomenon is that smartphones are very convenient for users to stay always connected to the Internet. In turn, this has led developers of smartphone apps to the assumption of continuous Internet connectivity. Therefore, many apps such as social network clients, weather forecasts, or instant messengers update their status frequently, which raises a number of problems¡ªin the mobile network as well as on the smartphones. In contrast to desktops or laptops, smartphones are equipped only with limited battery. Since established connections from the smartphone to the mobile network consume a large amount of energy, some smartphones close these connections soon after the data transmission is finished, that is, after a very short period of no traffic activity, which is controlled by an inactivity timer. This saves energy and prevents battery drain caused by established but unused connections. However, it
%U http://www.hindawi.com/journals/jcnc/2013/176217/