Today's mobile handheld devices, such as smartphones and action cameras, are well equipped for a wide range of multimedia and context-aware tasks. Such tasks can leverage traditional services like streaming audio and video as well as newer services like sensor fusion. Ubiquitous network access, coupled with an increasingly sophisticated mixture of device-based hardware and software, is enabling context-aware applications at an unprecedented rate. The objective of this chapter is to discuss specific quality attributes with respect to device-side software architectures providing these multimedia and sensor capabilities. This chapter focuses specifically on device-side client architectures rather than network or server architectures. Specific domain requirements and quality attributes are first derived through a synthesis of current research and industry trends, and subsequently analyzed. The analysis reveals some qualitative results that seem unintuitive at first glance but that become more understandable when provided with rationale relative to the handheld domain context.
TopIntroduction
Today's non-tablet, mobile handheld devices (i.e., smartphones) are well equipped for a wide range of multimedia and context-aware tasks (e.g., augmented reality). Already, current wireless and cellular technologies like Wi-Fi (802.11), 4G LTE, and HSPA+ enable streaming audio and video content to a wide range of mobile devices (Choi, Choi, and Bahk, 2007). Applications such as audio or video streaming, video conferencing, video surveillance, and web browser applications are migrating from PC/notebook computers to their handheld counterparts (Kim and Nieh, 2006). In addition, the complex mesh of sensors on many of today’s smart phones, combined with mobile data, enable completely new applications such as augmented reality (Wagner, 2012). The wide availability of sensors such as barometric altitude, gyroscopic rotation, and GPS sensors also enable new context-aware applications and usage modes. With handheld computing devices outnumbering conventional desktop systems in much of the developed world (GSMA Intelligence, 2014), both manufacturers and developers would do well to consider the special limitations inherent in the handheld domain. By giving careful consideration to quality attributes and their corresponding impact within this domain, manufacturers and developers are more likely to develop applications that work intelligently to mitigate shortcomings imposed by small-screened devices with limited battery life. The objective of this chapter is to discuss architectural attributes of multimedia frameworks on client-side mobile devices such as mobile phones and other handheld computers.
Our goal is to consolidate handheld factors such as power and screen size limitations in order to stimulate deeper consideration during software specification and design, particularly with respect to multimedia and contextual computing frameworks. The following sections further explain the motivation behind this objective and provide an overview of the chapter’s organization.
Currently, there is a lack of a standard approach to architectural evaluation for device side multimedia architectures in the handheld domain. This implies that handheld multimedia frameworks must be assessed more through trial and error than through a fitness assessment of some kind. Ultimately, this may lead to inflexible architectures that are difficult to modify later in the software’s lifetime. Not only that, but these architectures and the software built on top of them may not adequately address the availability, testability, and performance needs of software operating in the handheld domain. This problem, and its more specific incarnations are addressed in the research and observations section.