Mobile Intelligence

21.1 INTRODUCTION

Nowadays, handheld mobile devices including cell phones and personal digital assistants (PDAs) have become increasingly popular and capable, which creates new possibilities for accessing pervasive multimedia information. The new generation of mobile devices are no longer used only for voice communication, they are also used frequently to capture, manipulate, and display different audiovisual media contents.

With the rapid emergence of wireless network technologies, such as GSM, Satellite, Wireless Local Area Network (WLAN), and 3G, it is much easier now to transfer large size multimedia items to mobile clients. However, multimedia mobile services still suffer not only the constraints of small display sizes but also the limitation in terms of power supply, storage space, processing speed, among others. The navigation of multimedia contents on handheld devices is always restricted in the limited time periods with minimized amounts of interactions. Meanwhile, the large size multimedia data such as video cannot be stored permanently on the mobile devices due to the limited memory.

Take the following typical scenario in the mobile-based multimedia application. The sport fans wish to watch sports video through their cell phones. However, it is both unaffordable and sometime unnecessary for them to watch the whole game, which will take a long time, occupy huge memory, and exhaust the power supply. Thus, a better solution is to offer them the capability of browsing and ...